Fix bug in range analysis.

Fix bug in range analysis.

A definition that is in the same block as a phi can never
dominate the phi, since phis are at the very start of a block.

R=vegorov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=40102

[Florian Schneider, 2014-09-10 18:31:49]

fschneider@google.com changed reviewers:
+ vegorov@google.com

[Vyacheslav Egorov (Google), 2014-09-10 18:33:41]

lgtm

https://codereview.chromium.org/556353002/diff/1/runtime/vm/flow_graph_range_...
File runtime/vm/flow_graph_range_analysis.cc (right):

https://codereview.chromium.org/556353002/diff/1/runtime/vm/flow_graph_range_...
runtime/vm/flow_graph_range_analysis.cc:1828: return a->Dominates(phi_block) &&
(a != phi_block);
You reoder (a != phi_block) && ...

[Florian Schneider, 2014-09-10 18:56:49]

Committed patchset #1 (id:1) manually as r40102 (presubmit successful).