cps_ir: Constant fold lengths of constants

cps_ir: Constant fold lengths of constants

Replace GetLength of constant String and List values with the length.
This treats constants in line with known length container masks.

R=asgerf@google.com

Committed: https://github.com/dart-lang/sdk/commit/43c886d7522dffb4ddc606619c556f4f33c072ec

[sra1, 2015-11-25 04:37:33]

Description was changed from

==========
cps_ir: Constant fold lengths of constants

Replace GetLength of constant String and List values with the length.
This just treats constants in line with known length container masks.
==========

to

==========
cps_ir: Constant fold lengths of constants

Replace GetLength of constant String and List values with the length.
This treats constants in line with known length container masks.
==========

[sra1, 2015-11-25 04:37:33]

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

[asgerf, 2015-11-25 09:58:35]

lgtm

[sra1, 2015-11-25 18:15:32]

Description was changed from

==========
cps_ir: Constant fold lengths of constants

Replace GetLength of constant String and List values with the length.
This treats constants in line with known length container masks.
==========

to

==========
cps_ir: Constant fold lengths of constants

Replace GetLength of constant String and List values with the length.
This treats constants in line with known length container masks.

R=asgerf@google.com

Committed:
https://github.com/dart-lang/sdk/commit/43c886d7522dffb4ddc606619c556f4f33c072ec
==========

[sra1, 2015-11-25 18:15:33]

Committed patchset #1 (id:1) manually as
43c886d7522dffb4ddc606619c556f4f33c072ec (presubmit successful).