Fix incremental parsing of function literals in initializer lists.

Fix incremental parsing of function literals in initializer lists.

One of the areas in which the Dart grammar is context sensitive is the
fact that function literals are disallowed inside initializer lists
(unless they are enclosed inside (), [], {}, or "${}").

To deal with this context sentitivity in incremental parsing, we must
rebuild the correct parser state for the subexpression we are going to
re-parse before parsing it.  We do so with a new visitor,
IncrementalParseStateBuilder.

R=brianwilkerson@google.com

Committed: https://code.google.com/p/dart/source/detail?r=41813

[Paul Berry, 2014-11-18 22:35:44]

paulberry@google.com changed reviewers:
+ brianwilkerson@google.com

[Brian Wilkerson, 2014-11-18 22:44:58]

LGTM

[Paul Berry, 2014-11-18 22:50:15]

Committed patchset #1 (id:1) manually as 41813 (presubmit successful).