Add parser support for destructuring in formal parameter lists, and change the AST for default parameters to an ASSIGN node instead of a NAME node with a child.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70916600
Minor cleanups in the parser:
- Remove an unused variable
- Propagate the expressionIn parameter (corresponding to [In]s in the spec) when parsing arrow functions
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70959907
[NEW TYPE INFERENCE] Don't crash on mistyped assignment to an overriden function.

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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70962571
Lexing for unicode point escapes in identifiers. Scanning completed for unicode point escapes in string literals but more work is needed in the parser.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70969145
Unicode point escapes using ES6 {} notation for string literals.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70987551