Debugger: speed up setting break points in nested SFI.

Debugger: speed up setting break points in nested SFI.

If the shared function info is newly compiled when looking for
it in the script (Debug::FindSharedFunctionInfoInScript), then
we can bypass iterating the heap to find JSFunctions referencing
it (Debug::PrepareFunctionForBreakpoints).

BUG=v8:4553
LOG=N

Committed: https://crrev.com/de884f201ad9adf96a3c1ac4f99c23b5dd996e05
Cr-Commit-Position: refs/heads/master@{#32107}

[Yang, 2015-11-17 10:19:02]

Description was changed from

==========
Debugger: speed up setting break points in nested SFI.

If the shared function info is newly compiled when looking for
it in the script (Debug::FindSharedFunctionInfoInScript), then
we can bypass iterating the heap to find JSFunctions referencing
it (Debug::PrepareFunctionForBreakpoints).
==========

to

==========
Debugger: speed up setting break points in nested SFI.

If the shared function info is newly compiled when looking for
it in the script (Debug::FindSharedFunctionInfoInScript), then
we can bypass iterating the heap to find JSFunctions referencing
it (Debug::PrepareFunctionForBreakpoints).

BUG=v8:4553
LOG=N
==========

[Yang, 2015-11-18 07:25:10]

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

[Yang, 2015-11-18 14:47:25]

On 2015/11/18 07:25:10, Yang wrote:

Ulan, I fixed the condition. A bit different than what we discussed, but I think
this is correct and simpler.

[ulan, 2015-11-19 09:04:38]

lgtm

[Yang, 2015-11-19 09:47:47]

The CQ bit was checked by yangguo@chromium.org

[commit-bot: I haz the power, 2015-11-19 09:47:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1454673002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1454673002/40001

[commit-bot: I haz the power, 2015-11-19 10:38:33]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-11-19 10:39:17]

Patchset 3 (id:??) landed as
https://crrev.com/de884f201ad9adf96a3c1ac4f99c23b5dd996e05
Cr-Commit-Position: refs/heads/master@{#32107}