Simplify and correctify pending message location handling.

Simplify and correctify pending message location handling.

This makes sure that the pending message location is only tracked by
the message object, as only this is saved for finally-blocks. The
location information is duplicated and becomes stale.

R=titzer@chromium.org
TEST=maeh, not so much.

Committed: https://crrev.com/37729a52fdf3eaa4789612559e955d23328a2b8f
Cr-Commit-Position: refs/heads/master@{#27109}

[Michael Starzinger, 2015-03-10 13:45:07]

https://codereview.chromium.org/987353002/diff/1/src/isolate.cc
File src/isolate.cc (left):

https://codereview.chromium.org/987353002/diff/1/src/isolate.cc#oldcode1470
src/isolate.cc:1470: MessageLocation Isolate::GetMessageLocation() {
Please appreciate the fact that I can put UNREACHABLE() into this method and
still pass the entire test suite. That for sure instills confidence in our test
coverage.

[titzer, 2015-03-10 13:48:24]

lgtm

https://codereview.chromium.org/987353002/diff/1/src/isolate.cc
File src/isolate.cc (left):

https://codereview.chromium.org/987353002/diff/1/src/isolate.cc#oldcode1470
src/isolate.cc:1470: MessageLocation Isolate::GetMessageLocation() {
On 2015/03/10 13:45:07, Michael Starzinger wrote:
> Please appreciate the fact that I can put UNREACHABLE() into this method and
> still pass the entire test suite. That for sure instills confidence in our
test
> coverage.

Yeah, given that you showed me that this is only called in LiveEdit, then it
must not be critical enough that someone bothered testing it.

[Michael Starzinger, 2015-03-10 14:07:09]

The CQ bit was checked by mstarzinger@chromium.org

[commit-bot: I haz the power, 2015-03-10 14:08:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/987353002/1

[commit-bot: I haz the power, 2015-03-10 14:45:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-10 14:45:37]

Patchset 1 (id:??) landed as
https://crrev.com/37729a52fdf3eaa4789612559e955d23328a2b8f
Cr-Commit-Position: refs/heads/master@{#27109}