[turbofan] Fix undefined behavior in InstructionSequence::GetInstructionBlock.

[turbofan] Fix undefined behavior in InstructionSequence::GetInstructionBlock.

Some implementations of std::lower_bound require weak-strict ordering.

The comparison operator must be assymetric, which doesn't hold for less_equals.

Committed: https://crrev.com/47bcd1a139451204667949ee4836724b64fb2996
Cr-Commit-Position: refs/heads/master@{#29633}

[ulan, 2015-07-13 10:52:18]

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

[ulan, 2015-07-13 10:52:18]

PTAL

[Benedikt Meurer, 2015-07-14 02:50:42]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-07-14 02:50:43]

lgtm

[commit-bot: I haz the power, 2015-07-14 02:50:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1232613002/1

[commit-bot: I haz the power, 2015-07-14 03:33:24]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-14 03:33:37]

Patchset 1 (id:??) landed as
https://crrev.com/47bcd1a139451204667949ee4836724b64fb2996
Cr-Commit-Position: refs/heads/master@{#29633}