v8: Fix unaligned access when deserializing snapshots.

v8: Fix unaligned access when deserializing snapshots.

The code was already careful to use memcpy() here, but then it
added needless casts to wider types that made the compiler think
that it can do 4-byte-aligned accesses when it couldn't.

(It's also a bug that the snapshot got loaded at an unaligned
address, but we can fix both bugs.)

BUG=chromium:729059
Review-Url: https://codereview.chromium.org/2915323002
Cr-Commit-Position: refs/heads/master@{#45698}
Committed: https://chromium.googlesource.com/v8/v8/+/13af45c91dac27dffc7d25ca902fb81630b49ca4

[Nico, 2017-06-02 18:26:37]

The CQ bit was checked by thakis@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-06-02 18:26:39]

Dry run: CQ is trying da patch.

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

[Nico, 2017-06-02 18:27:01]

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

[commit-bot: I haz the power, 2017-06-02 18:55:30]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-06-02 18:55:31]

Dry run: This issue passed the CQ dry run.

[adamk, 2017-06-02 19:08:55]

adamk@chromium.org changed reviewers:
+ verwaest@chromium.org, vogelheim@chromium.org
- yangguo@chromium.org

[adamk, 2017-06-02 19:08:55]

-yang, +other owners not on leave

[Yang, 2017-06-02 19:46:05]

On 2017/06/02 19:08:55, adamk wrote:
> -yang, +other owners not on leave

lgtm

[Nico, 2017-06-02 19:47:26]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2017-06-02 19:47:33]

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, 2017-06-02 19:48:50]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496432846729710, "parent_rev":
"7ef542dc4a0b244044880b5259c66e641b4a311e", "commit_rev":
"13af45c91dac27dffc7d25ca902fb81630b49ca4"}

[commit-bot: I haz the power, 2017-06-02 19:48:57]

Description was changed from

==========
v8: Fix unaligned access when deserializing snapshots.

The code was already careful to use memcpy() here, but then it
added needless casts to wider types that made the compiler think
that it can do 4-byte-aligned accesses when it couldn't.

(It's also a bug that the snapshot got loaded at an unaligned
address, but we can fix both bugs.)

BUG=chromium:729059
==========

to

==========
v8: Fix unaligned access when deserializing snapshots.

The code was already careful to use memcpy() here, but then it
added needless casts to wider types that made the compiler think
that it can do 4-byte-aligned accesses when it couldn't.

(It's also a bug that the snapshot got loaded at an unaligned
address, but we can fix both bugs.)

BUG=chromium:729059

Review-Url: https://codereview.chromium.org/2915323002
Cr-Commit-Position: refs/heads/master@{#45698}
Committed:
https://chromium.googlesource.com/v8/v8/+/13af45c91dac27dffc7d25ca902fb81630b...
==========

[commit-bot: I haz the power, 2017-06-02 19:48:58]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/13af45c91dac27dffc7d25ca902fb81630b...