Clean up JSConstructStub

Clean up JSConstructStub

- fix truthfulness of comments
- use InitializeFieldsWithFiller more consistently
- use unsigned comparisons for pointers

No change in functionality intended.

Bonus: improve JavaScriptFrame::Print() for an enhanced debugging experience:

- print PC of each frame
- print the function's source also for optimized frames

Committed: https://crrev.com/882055ff6a58f6b585575229f40f364e5f2a3ad0
Cr-Commit-Position: refs/heads/master@{#29082}

[Jakob Kummerow, 2015-06-16 12:34:09]

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

[Jakob Kummerow, 2015-06-16 12:34:10]

Some fallout from my last debugging session...

[Benedikt Meurer, 2015-06-17 03:21:39]

LGTM with nit.

https://codereview.chromium.org/1186823003/diff/20001/src/frames.cc
File src/frames.cc (right):

https://codereview.chromium.org/1186823003/diff/20001/src/frames.cc#newcode1050
src/frames.cc:1050: static void PrintFunctionSource(StringStream* accumulator,
Nit: Put into anonymous namespace instead of using static here.

[Jakob Kummerow, 2015-06-17 11:23:45]

Thanks, CQ'ing.

https://codereview.chromium.org/1186823003/diff/20001/src/frames.cc
File src/frames.cc (right):

https://codereview.chromium.org/1186823003/diff/20001/src/frames.cc#newcode1050
src/frames.cc:1050: static void PrintFunctionSource(StringStream* accumulator,
On 2015/06/17 03:21:39, Benedikt Meurer wrote:
> Nit: Put into anonymous namespace instead of using static here.

Done.

[Jakob Kummerow, 2015-06-17 11:23:59]

The CQ bit was checked by jkummerow@chromium.org

[Jakob Kummerow, 2015-06-17 11:24:00]

The patchset sent to the CQ was uploaded after l-g-t-m from bmeurer@chromium.org
Link to the patchset: https://codereview.chromium.org/1186823003/#ps60001
(title: "rebased")

[commit-bot: I haz the power, 2015-06-17 11:24:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1186823003/60001

[commit-bot: I haz the power, 2015-06-17 11:58:23]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-06-17 11:58:35]

Patchset 4 (id:??) landed as
https://crrev.com/882055ff6a58f6b585575229f40f364e5f2a3ad0
Cr-Commit-Position: refs/heads/master@{#29082}