X87: Debugger: prepare code for debugging on a per-function basis.

X87: Debugger: prepare code for debugging on a per-function basis.

port 35c28ce0a742e58346d2dea009428cacd442040d (r29758).

original commit message:

    Prior to this patch, we enter a global debug mode whenever a break point
    is set. By entering this mode, all code is deoptimized and activated
    frames are recompiled and redirected to newly compiled debug code.

    After this patch, we only deoptimize/redirect for functions we want to
    debug. Trigger for this is Debug::EnsureDebugInfo, and having DebugInfo
    object attached to the SFI prevents optimization/inlining.

    The result is that we can have optimized code for functions without break
    points alongside functions that do have break points, which are not
    optimized.

BUG=

Committed: https://crrev.com/65f18c9d6cd8871615c18a0d7af9c2b8838c99c8
Cr-Commit-Position: refs/heads/master@{#29765}

[chunyang.dai, 2015-07-21 02:26:22]

chunyang.dai@intel.com changed reviewers:
+ weiliang.lin@intel.com

[chunyang.dai, 2015-07-21 02:26:23]

PTAL

[Weiliang, 2015-07-21 02:29:54]

The CQ bit was checked by weiliang.lin@intel.com

[Weiliang, 2015-07-21 02:29:54]

lgtm

[commit-bot: I haz the power, 2015-07-21 02:30:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1249503002/1

[commit-bot: I haz the power, 2015-07-21 02:52:24]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-21 02:52:43]

Patchset 1 (id:??) landed as
https://crrev.com/65f18c9d6cd8871615c18a0d7af9c2b8838c99c8
Cr-Commit-Position: refs/heads/master@{#29765}