Try to avoid checks for lazy initialization when recompiling.

Try to avoid checks for lazy initialization when recompiling.

When recompiling implicit static getters, it can happen that the field
is already initialized.  In this case parse the getter to a field load
instead of a pair of sentinel checks and initialization code.

R=srdjan@google.com

Committed: https://code.google.com/p/dart/source/detail?r=24122

[srdjan, 2013-06-17 18:31:32]

LGTM

[Kevin Millikin (Google), 2013-06-18 06:55:41]

Committed patchset #1 manually as r24122 (presubmit successful).