Drop some amount of corejs also the file in git tree

Reasons for doing it this way:
1. this lets us easily see what is actually included in the fina core-js
   build by looking at k6-shim.js. The format there is probably going to
   change as it is copied from the core-js repo's shim.js, but the idea
   will stay
2. There is no need to have the shim.min.js in the git tree as it is
   already in lib/rice-box.go. Maybe after the golang embed proposal is
   available we can switch around, but this will likely take more then a
   year before we don't need to support a version of golang without it
3. go generate is awesome, but in this case it has way too many things
   that need to happen which makes it IMO a bad fit. This plus the fact
   that this will not be changed regularly means it is probably better
   this way.

js/bundle_test.go

@@ -114,12 +114,18 @@ func TestNewBundle(t *testing.T) {
 		}
 	})
 	t.Run("CompatibilityMode", func(t *testing.T) {
+		compatibilityTestSrc := `
+		module.exports.default = function() {};
+		if ([[1,2],[3,4]].flatten()[4]  == 4) {
+			throw Error("Array.flatten doesn't work")
+		}
+		`
+
 		t.Run("Extended/ok/CoreJS", func(t *testing.T) {
 			rtOpts := lib.RuntimeOptions{
 				CompatibilityMode: null.StringFrom(lib.CompatibilityModeExtended.String()),
 			}
-			_, err := getSimpleBundle(t, "/script.js",
-				`module.exports.default = function() {}; new Promise(function(resolve, reject){});`, rtOpts)
+			_, err := getSimpleBundle(t, "/script.js", compatibilityTestSrc, rtOpts)
 
 			assert.NoError(t, err)
 		})
@@ -156,8 +162,8 @@ func TestNewBundle(t *testing.T) {
 				// some ES2015 objects polyfilled by core.js are not supported
 				{
 					"CoreJS", "base",
-					`module.exports.default = function() {}; new Promise(function(resolve, reject){});`,
-					"ReferenceError: Promise is not defined at file:///script.js:1:45(5)",
+					compatibilityTestSrc,
+					"TypeError: Object has no member 'flatten' at file:///script.js:3:28(14)",
 				},
 			}
 

js/lib/build.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+sha="a3616d74c0b9b9409d580337e04c32da6e3877e4" # v2.5.1
+mkdir -p ./corejs-repo
+cd ./corejs-repo
+git init
+git remote add origin https://github.com/zloirock/core-js.git
+git fetch origin --depth=1 "${sha}"
+git reset --hard "${sha}"
+cp ../k6-shim.js shim.js
+cp ../corejs-build.sh corejs-build.sh
+docker run --user "$UID:$GID" --rm -ti  -v $(pwd):/opt/g --entrypoint /opt/g/corejs-build.sh --workdir /opt/g node
+cp custom.min.js ../shim.min.js
+cd -
+rm -rf corejs-repo
+mkdir core-js
+mv shim.min.js core-js/shim.min.js
+rice embed-go
+rm -rf core-js

js/lib/corejs-build.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+npm i .
+modules="$(cat shim.js | grep ^require  | sed "s|require('\./modules/||g"  | sed "s/');//g" | tr "\n" ",")"
+npm run grunt "build:${modules}" "--library=off" "--path=custom" "uglify"

js/lib/k6-shim.js

@@ -0,0 +1,198 @@
+//require('./modules/es6.symbol'); // in goja or promises
+//require('./modules/es6.object.create');
+//require('./modules/es6.object.define-property');
+//require('./modules/es6.object.define-properties');
+//require('./modules/es6.object.get-own-property-descriptor');
+//require('./modules/es6.object.get-prototype-of');
+//require('./modules/es6.object.keys');
+//require('./modules/es6.object.get-own-property-names');
+//require('./modules/es6.object.freeze');
+//require('./modules/es6.object.seal');
+//require('./modules/es6.object.prevent-extensions');
+//require('./modules/es6.object.is-frozen');
+//require('./modules/es6.object.is-sealed');
+//require('./modules/es6.object.is-extensible');
+//require('./modules/es6.object.assign');
+//require('./modules/es6.object.is');
+//require('./modules/es6.object.set-prototype-of');
+//require('./modules/es6.object.to-string');
+//require('./modules/es6.function.bind');
+//require('./modules/es6.function.name');
+//require('./modules/es6.function.has-instance');
+//require('./modules/es6.parse-int');
+//require('./modules/es6.parse-float');
+//require('./modules/es6.number.constructor');
+//require('./modules/es6.number.to-fixed');
+//require('./modules/es6.number.to-precision');
+//require('./modules/es6.number.epsilon');
+//require('./modules/es6.number.is-finite');
+//require('./modules/es6.number.is-integer');
+//require('./modules/es6.number.is-nan');
+//require('./modules/es6.number.is-safe-integer');
+//require('./modules/es6.number.max-safe-integer');
+//require('./modules/es6.number.min-safe-integer');
+//require('./modules/es6.number.parse-float');
+//require('./modules/es6.number.parse-int');
+//require('./modules/es6.math.acosh');
+//require('./modules/es6.math.asinh');
+//require('./modules/es6.math.atanh');
+//require('./modules/es6.math.cbrt');
+//require('./modules/es6.math.clz32');
+//require('./modules/es6.math.cosh');
+//require('./modules/es6.math.expm1');
+//require('./modules/es6.math.fround');
+//require('./modules/es6.math.hypot');
+//require('./modules/es6.math.imul');
+//require('./modules/es6.math.log10');
+//require('./modules/es6.math.log1p');
+//require('./modules/es6.math.log2');
+//require('./modules/es6.math.sign');
+//require('./modules/es6.math.sinh');
+//require('./modules/es6.math.tanh');
+//require('./modules/es6.math.trunc');
+//require('./modules/es6.string.from-code-point');
+//require('./modules/es6.string.raw');
+//require('./modules/es6.string.trim');
+//require('./modules/es6.string.iterator');
+//require('./modules/es6.string.code-point-at');
+//require('./modules/es6.string.ends-with');
+//require('./modules/es6.string.includes');
+//require('./modules/es6.string.repeat');
+//require('./modules/es6.string.starts-with');
+//require('./modules/es6.string.anchor');
+//require('./modules/es6.string.big');
+//require('./modules/es6.string.blink');
+//require('./modules/es6.string.bold');
+//require('./modules/es6.string.fixed');
+//require('./modules/es6.string.fontcolor');
+//require('./modules/es6.string.fontsize');
+//require('./modules/es6.string.italics');
+//require('./modules/es6.string.link');
+//require('./modules/es6.string.small');
+//require('./modules/es6.string.strike');
+//require('./modules/es6.string.sub');
+//require('./modules/es6.string.sup');
+//require('./modules/es6.date.now');
+//require('./modules/es6.date.to-json');
+//require('./modules/es6.date.to-iso-string');
+//require('./modules/es6.date.to-string');
+//require('./modules/es6.date.to-primitive');
+//require('./modules/es6.array.is-array');
+//require('./modules/es6.array.from');
+//require('./modules/es6.array.of');
+//require('./modules/es6.array.join');
+//require('./modules/es6.array.slice');
+//require('./modules/es6.array.sort');
+//require('./modules/es6.array.for-each');
+//require('./modules/es6.array.map');
+//require('./modules/es6.array.filter');
+//require('./modules/es6.array.some');
+//require('./modules/es6.array.every');
+//require('./modules/es6.array.reduce');
+//require('./modules/es6.array.reduce-right');
+//require('./modules/es6.array.index-of');
+//require('./modules/es6.array.last-index-of');
+//require('./modules/es6.array.copy-within');
+//require('./modules/es6.array.fill');
+//require('./modules/es6.array.find');
+//require('./modules/es6.array.find-index');
+//require('./modules/es6.array.species');
+//require('./modules/es6.array.iterator');
+//require('./modules/es6.regexp.constructor');
+//require('./modules/es6.regexp.to-string');
+//require('./modules/es6.regexp.flags');
+//require('./modules/es6.regexp.match');
+//require('./modules/es6.regexp.replace');
+//require('./modules/es6.regexp.search');
+//require('./modules/es6.regexp.split');
+//require('./modules/es6.promise');
+//require('./modules/es6.map');
+//require('./modules/es6.set');
+//require('./modules/es6.weak-map');
+//require('./modules/es6.weak-set');
+//require('./modules/es6.typed.array-buffer');
+//require('./modules/es6.typed.data-view');
+//require('./modules/es6.typed.int8-array');
+//require('./modules/es6.typed.uint8-array');
+//require('./modules/es6.typed.uint8-clamped-array');
+//require('./modules/es6.typed.int16-array');
+//require('./modules/es6.typed.uint16-array');
+//require('./modules/es6.typed.int32-array');
+//require('./modules/es6.typed.uint32-array');
+//require('./modules/es6.typed.float32-array');
+//require('./modules/es6.typed.float64-array');
+//require('./modules/es6.reflect.apply');
+//require('./modules/es6.reflect.construct');
+//require('./modules/es6.reflect.define-property');
+//require('./modules/es6.reflect.delete-property');
+//require('./modules/es6.reflect.enumerate');
+//require('./modules/es6.reflect.get');
+//require('./modules/es6.reflect.get-own-property-descriptor');
+//require('./modules/es6.reflect.get-prototype-of');
+//require('./modules/es6.reflect.has');
+//require('./modules/es6.reflect.is-extensible');
+//require('./modules/es6.reflect.own-keys');
+//require('./modules/es6.reflect.prevent-extensions');
+//require('./modules/es6.reflect.set');
+//require('./modules/es6.reflect.set-prototype-of');
+//require('./modules/es7.array.includes'); // in goja
+require('./modules/es7.array.flat-map');
+// this is now called flat, so maybe drop it https://github.com/tc39/proposal-flatMap 
+require('./modules/es7.array.flatten');
+//require('./modules/es7.string.at'); // it is in es2020 but is with completely different semantics
+//require('./modules/es7.string.pad-start'); // in goja
+//require('./modules/es7.string.pad-end'); // in goja
+require('./modules/es7.string.trim-left');
+require('./modules/es7.string.trim-right');
+require('./modules/es7.string.match-all');
+//require('./modules/es7.symbol.async-iterator'); // async
+//require('./modules/es7.symbol.observable');
+require('./modules/es7.object.get-own-property-descriptors');
+require('./modules/es7.object.values');
+require('./modules/es7.object.entries');
+require('./modules/es7.object.define-getter');
+require('./modules/es7.object.define-setter');
+require('./modules/es7.object.lookup-getter');
+require('./modules/es7.object.lookup-setter');
+// require('./modules/es7.map.to-json'); // not actually in the standard
+//require('./modules/es7.set.to-json');
+//require('./modules/es7.map.of');
+//require('./modules/es7.set.of');
+//require('./modules/es7.weak-map.of');
+//require('./modules/es7.weak-set.of');
+//require('./modules/es7.map.from');
+//require('./modules/es7.set.from');
+//require('./modules/es7.weak-map.from');
+//require('./modules/es7.weak-set.from');
+//require('es7.global'); // is now globalThis, goja has globasl
+//require('es7.system.global'); // dropped .. I think
+//require('es7.error.is-error'); // dropped
+//require('./modules/es7.math.clamp'); // not actually in the standard
+//require('./modules/es7.math.deg-per-rad');
+//require('./modules/es7.math.degrees');
+//require('./modules/es7.math.fscale');
+//require('./modules/es7.math.iaddh');
+//require('./modules/es7.math.isubh');
+//require('./modules/es7.math.imulh');
+//require('./modules/es7.math.rad-per-deg');
+//require('./modules/es7.math.radians');
+//require('./modules/es7.math.scale');
+//require('./modules/es7.math.umulh');
+//require('./modules/es7.math.signbit');
+//require('./modules/es7.promise.finally'); // promises
+//require('./modules/es7.promise.try');
+require('./modules/es7.reflect.define-metadata');
+require('./modules/es7.reflect.delete-metadata');
+require('./modules/es7.reflect.get-metadata');
+require('./modules/es7.reflect.get-metadata-keys');
+require('./modules/es7.reflect.get-own-metadata');
+require('./modules/es7.reflect.get-own-metadata-keys');
+require('./modules/es7.reflect.has-metadata');
+require('./modules/es7.reflect.has-own-metadata');
+require('./modules/es7.reflect.metadata');
+//require('./modules/es7.asap'); // promises
+//require('./modules/es7.observable');
+//require('./modules/web.timers'); // web stuff
+//require('./modules/web.immediate');
+//require('./modules/web.dom.iterable');
+// module.exports = require('./modules/_core');

js/lib/lib.go

@@ -18,8 +18,6 @@
  *
  */
 
-//go:generate rice embed-go
-
 package lib
 
 import (