https://bugs.webkit.org/show_bug.cgi?id=124172

Reviewed by Mark Lam.

Source/JavaScriptCore:

Add support for unprefixed descontructive assignment.

Happily non-reference types on the left hand side of an assignment
are a runtime error, so we're able to defer validation of the binding
pattern to codegen time when we're already doing a lot more work.

We're also able to predicate our attempt to parse on the existence of
'[' or '{' as they are not as common as other constructs.

* bytecompiler/NodesCodegen.cpp:
(JSC::ArrayPatternNode::emitDirectBinding):
* parser/ASTBuilder.h:
* parser/Parser.cpp:
(JSC::::createBindingPattern):
(JSC::::tryParseDeconstructionPatternExpression):
(JSC::::parseDeconstructionPattern):
(JSC::::parseForStatement):
(JSC::::parseAssignmentExpression):
* parser/Parser.h:
(JSC::Parser::createSavePoint):
(JSC::Parser::restoreSavePoint):
* parser/SyntaxChecker.h:

LayoutTests:

Add and expand testing of destructuring assignment

* js/basic-for-of-expected.txt:
* js/destructuring-assignment-expected.txt:
* js/parser-syntax-check-expected.txt:
* js/script-tests/basic-for-of.js:
* js/script-tests/destructuring-assignment.js:
(testDestructuring):
* js/script-tests/parser-syntax-check.js:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@159139 268f45cc-cd09-0410-ab3c-d52691b4dbfc