Attempt #<really big number>

Parses, and lazily rewrites Destructuring Assignment expressions. The rewriting strategy involves inserting a placeholder RewritableAssignmentExpression into the AST, whose content expression can be completely rewritten at a later time.

Lazy rewriting ensures that errors do not occur due to eagerly rewriting nodes which form part of a binding pattern, thus breaking the meaning of the pattern --- or by eagerly rewriting ambiguous constructs that are not immediately known

BUG=v8:811
LOG=Y
R=adamk@chromium.org, bmeurer@chromium.org, rossberg@chromium.org

Review URL: https://codereview.chromium.org/1309813007

Cr-Commit-Position: refs/heads/master@{#32623}