[turbofan] Introduce new Select operator to improve bounds checking.

[turbofan] Introduce new Select operator to improve bounds checking.

TEST=mjsunit,unittests
R=dcarney@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=24980

[Benedikt Meurer, 2014-10-29 14:04:14]

bmeurer@chromium.org changed reviewers:
+ dcarney@chromium.org

[Benedikt Meurer, 2014-10-29 14:04:14]

PTAL

[Benedikt Meurer, 2014-10-29 14:04:42]

Note: It's still not 64-bit clean, i.e. store/load indices are probably broken.
Have to fix that in a follow up CL.

[dcarney, 2014-10-29 14:15:17]

lgtm

[Benedikt Meurer, 2014-10-29 14:16:54]

Committed patchset #1 (id:1) manually as 24980 (tree was closed).