Fix issue 10321 by invalidating previous "generate at use site" optimizations based on a pure instr…

Fix issue 10321 by invalidating previous "generate at use site" optimizations based on a pure instruction that is being moved in the graph.

R=ahe@google.com, kasperl@google.com

Committed: https://code.google.com/p/dart/source/detail?r=22232

[ahe, 2013-04-30 20:06:25]

LGTM, I can confirm that sunflower now runs on self-hosted dart2js.

https://codereview.chromium.org/14602011/diff/1/sdk/lib/_internal/compiler/im...
File sdk/lib/_internal/compiler/implementation/ssa/codegen_helpers.dart (right):

https://codereview.chromium.org/14602011/diff/1/sdk/lib/_internal/compiler/im...
sdk/lib/_internal/compiler/implementation/ssa/codegen_helpers.dart:63: //
non-nure, non-code motion invariant, instructions need
nure -> pure

[ngeoffray, 2013-05-01 09:37:09]

Thanks Peter for having taken a look. The fix actually did not compose when a
pure instruction was using another pure instruction. I added a test and fixed
the CL, PTAL.

[kasperl, 2013-05-01 09:39:31]

LGTM.

[ngeoffray, 2013-05-01 09:49:14]

Committed patchset #2 manually as r22232 (presubmit successful).