PPC/s390: [liveedit] reimplement frame restarting.

PPC/s390: [liveedit] reimplement frame restarting.

Port 3f47c63ded839194989ba69c3039ea073636ef30

Original Commit Message:

    Previously, when restarting a frame, we would rewrite all frames
    between the debugger activation and the frame to restart to squash
    them, and replace the return address with that of a builtin to
    leave that rewritten frame, and restart the function by calling it.

    We now simply remember the frame to drop to, and upon returning
    from the debugger, we check whether to drop the frame, load the
    new FP, and restart the function.

R=yangguo@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:5587
LOG=N

Review-Url: https://codereview.chromium.org/2663453004
Cr-Commit-Position: refs/heads/master@{#42748}
Committed: https://chromium.googlesource.com/v8/v8/+/9515f7edf0702015bf026211790cfc0e48378023

[JaideepBajwa, 2017-01-27 18:58:28]

ptal

[john.yan, 2017-01-27 19:00:25]

lgtm

[JaideepBajwa, 2017-01-27 19:12:02]

The CQ bit was checked by bjaideep@ca.ibm.com

[commit-bot: I haz the power, 2017-01-27 19:12:12]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-27 19:43:59]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1485544322953470, "parent_rev":
"82ef9f75e343bb49f99a6f39f8c280bf3ef42b64", "commit_rev":
"9515f7edf0702015bf026211790cfc0e48378023"}

[commit-bot: I haz the power, 2017-01-27 19:44:05]

Description was changed from

==========
PPC/s390: [liveedit] reimplement frame restarting.

Port 3f47c63ded839194989ba69c3039ea073636ef30

Original Commit Message:

    Previously, when restarting a frame, we would rewrite all frames
    between the debugger activation and the frame to restart to squash
    them, and replace the return address with that of a builtin to
    leave that rewritten frame, and restart the function by calling it.

    We now simply remember the frame to drop to, and upon returning
    from the debugger, we check whether to drop the frame, load the
    new FP, and restart the function.

R=yangguo@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=v8:5587
LOG=N
==========

to

==========
PPC/s390: [liveedit] reimplement frame restarting.

Port 3f47c63ded839194989ba69c3039ea073636ef30

Original Commit Message:

    Previously, when restarting a frame, we would rewrite all frames
    between the debugger activation and the frame to restart to squash
    them, and replace the return address with that of a builtin to
    leave that rewritten frame, and restart the function by calling it.

    We now simply remember the frame to drop to, and upon returning
    from the debugger, we check whether to drop the frame, load the
    new FP, and restart the function.

R=yangguo@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=v8:5587
LOG=N

Review-Url: https://codereview.chromium.org/2663453004
Cr-Commit-Position: refs/heads/master@{#42748}
Committed:
https://chromium.googlesource.com/v8/v8/+/9515f7edf0702015bf026211790cfc0e483...
==========

[commit-bot: I haz the power, 2017-01-27 19:44:06]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/9515f7edf0702015bf026211790cfc0e483...