Added tests.
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Merge pull request #1268 from Microsoft/generators

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Merge branch 'master' into conformanceTests-624

Conflicts:
	tests/baselines/reference/parameterInitializersForwardReferencing.errors.txt
Merge pull request #657 from Microsoft/conformanceTests-624

Conformance Tests for Spec Change in PR#624
- cleaned up rewriter
- fixed label fall-through
- added implicit return
- disallow 'with' in async
- fixed ASI ambiguity with 'async' by disallowing newline
- cleanup rewrite of ForInStatement
Fixed whitespace in Jakefile
merged 'master' to 'prototypeAsync'