fix(@angular/cli): allow -a=value arguments

If a flag is followed by an equal sign, just treat it as a long name. So
the example above would translate to --a=value, while -abc=123 would be
"-a -b -c=123".

Fixes #12308

packages/angular/cli/models/parser.ts

@@ -281,6 +281,12 @@ export function parseArguments(args: string[], options: Option[] | null): Argume
       // Argument is of form -abcdef.  Starts at 1 because we skip the `-`.
       for (let i = 1; i < arg.length; i++) {
         const flag = arg[i];
+        // If the next character is an '=', treat it as a long flag.
+        if (arg[i + 1] == '=') {
+          const f = '--' + flag + arg.slice(i + 1);
+          _assignOption(f, args, options, parsedOptions, positionals, leftovers, ignored, errors);
+          break;
+        }
         // Treat the last flag as `--a` (as if full flag but just one letter). We do this in
         // the loop because it saves us a check to see if the arg is just `-`.
         if (i == arg.length - 1) {

packages/angular/cli/models/parser_spec.ts

@@ -80,7 +80,9 @@ describe('parseArguments', () => {
     '--noHelloBool': { helloBool: false },
     '--noBool': { bool: false },
     '-b': { bool: true },
+    '-b=true': { bool: true },
     '-sb': { bool: true, str: '' },
+    '-s=b': { str: 'b' },
     '-bs': { bool: true, str: '' },
     '--t1=true': { t1: true },
     '--t1': { t1: true },