Bit width analysis for avoiding conversion of bitops to unsigned.

Bit width analysis for avoiding conversion of bitops to unsigned.

R=sigmund@google.com

Committed: https://github.com/dart-lang/sdk/commit/a5443a8b0d983eda457996b8534646154a59c334

Reverted:  https://github.com/dart-lang/sdk/commit/08854375b316f285588a8a51dd379bad4da26c6f

[sra1, 2016-11-16 19:23:48]

sra@google.com changed reviewers:
+ sigmund@google.com

[sra1, 2016-11-16 19:23:48]

I have has this lying around for a while.
This is essentially the same analysis I wrote for DDC.

[Siggi Cherem (dart-lang), 2016-11-16 19:31:15]

lgtm

[sra1, 2016-11-16 21:37:22]

Description was changed from

==========
Bit width analysis for avoiding conversion of bitops to unsigned.
==========

to

==========
Bit width analysis for avoiding conversion of bitops to unsigned.

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/a5443a8b0d983eda457996b8534646154a59c334
==========

[sra1, 2016-11-16 21:37:24]

Committed patchset #2 (id:20001) manually as
a5443a8b0d983eda457996b8534646154a59c334 (presubmit successful).

[sra1, 2016-11-16 21:57:06]

Description was changed from

==========
Bit width analysis for avoiding conversion of bitops to unsigned.

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/a5443a8b0d983eda457996b8534646154a59c334
==========

to

==========
Bit width analysis for avoiding conversion of bitops to unsigned.

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/a5443a8b0d983eda457996b8534646154a59c334

Reverted: 
https://github.com/dart-lang/sdk/commit/08854375b316f285588a8a51dd379bad4da26c6f
==========