fix($compile): throw error in $onChanges immediately

This brings it in line with how we throw errors in a digest cycle, 
and also avoids throwing an array.

Closes #15578 
Closes #16492

src/ng/compile.js

@@ -1557,19 +1557,15 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
         }
         // We must run this hook in an apply since the $$postDigest runs outside apply
         $rootScope.$apply(function() {
-          var errors = [];
           for (var i = 0, ii = onChangesQueue.length; i < ii; ++i) {
             try {
               onChangesQueue[i]();
             } catch (e) {
-              errors.push(e);
+              $exceptionHandler(e);
             }
           }
           // Reset the queue to trigger a new schedule next time there is a change
           onChangesQueue = undefined;
-          if (errors.length) {
-            throw errors;
-          }
         });
       } finally {
         onChangesTtl++;

test/ng/compileSpec.js

@@ -5075,16 +5075,15 @@ describe('$compile', function() {
           $rootScope.$apply('a = 42');
 
           // The first component's error should be logged
-          var errors = $exceptionHandler.errors.pop();
-          expect(errors[0]).toEqual(new Error('bad hook'));
+          expect($exceptionHandler.errors.pop()).toEqual(new Error('bad hook'));
 
           // The second component's changes should still be called
           expect($log.info.logs.pop()).toEqual(['onChange']);
         });
       });
 
 
-      it('should collect up all `$onChanges` errors into one throw', function() {
+      it('should throw `$onChanges` errors immediately', function() {
         function ThrowingController() {
           this.$onChanges = function(change) {
             throw new Error('bad hook: ' + this.prop);
@@ -5113,10 +5112,9 @@ describe('$compile', function() {
 
           $rootScope.$apply('a = 42');
 
-          // Both component's error should be logged
-          var errors = $exceptionHandler.errors.pop();
-          expect(errors.pop()).toEqual(new Error('bad hook: 84'));
-          expect(errors.pop()).toEqual(new Error('bad hook: 42'));
+          // Both component's error should be logged individually
+          expect($exceptionHandler.errors.pop()).toEqual(new Error('bad hook: 84'));
+          expect($exceptionHandler.errors.pop()).toEqual(new Error('bad hook: 42'));
         });
       });
     });