Ensure external snapshot is only set once.

BUG=421063

Review URL: https://codereview.chromium.org/746263002

Cr-Commit-Position: refs/heads/master@{#25481}
Reland of "TransitionArray::Search() now returns insertion index if the entry was not found."

Review URL: https://codereview.chromium.org/739013004

Cr-Commit-Position: refs/heads/master@{#25482}
Reland of "Enable inobject double fields unboxing for 64-bit archs."

Review URL: https://codereview.chromium.org/751643005

Cr-Commit-Position: refs/heads/master@{#25483}
Dictionary-mode PropertyDetails printing fixed.

BUG=chromium:435974
LOG=N

Review URL: https://codereview.chromium.org/755583003

Cr-Commit-Position: refs/heads/master@{#25484}
Make use of post-scoping information to compute feedback vector requirements.

This avoids allocating vector ic slots that we don't use.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/758543002

Cr-Commit-Position: refs/heads/master@{#25485}
Correctly find shared function info for debugging when compiling eagerly.

R=ulan@chromium.org
BUG=v8:3717
LOG=N

Review URL: https://codereview.chromium.org/758523004

Cr-Commit-Position: refs/heads/master@{#25486}
Remove v8::StartupData::compressed_size.

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/739253006

Cr-Commit-Position: refs/heads/master@{#25487}
Remove lineprocessor sample.

This sample used to demonstrate the usage of the DebuggerAgent. The latter
has been removed, so this sample has no point anymore.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/754043002

Cr-Commit-Position: refs/heads/master@{#25488}
Disable regress-3717 for gc-stress.

TBR=ulan@chromium.org
BUG=v8:3723
LOG=N

Review URL: https://codereview.chromium.org/749283002

Cr-Commit-Position: refs/heads/master@{#25489}
Load prototype from map in PropertyHandlerCompiler::CheckPrototypes.

BUG=v8:3629
LOG=N
TBR=verwaest@chromium.org

Review URL: https://codereview.chromium.org/753223002

Cr-Commit-Position: refs/heads/master@{#25490}
[turbofan] Fix matching of the lea instruction.

Resets the scaled exponent to 0 when the scaling match fails.

BUG=

Review URL: https://codereview.chromium.org/756643002

Cr-Commit-Position: refs/heads/master@{#25491}
Fix/suppress unittests broken on Android

cctest/test-threads/ThreadJoinSelf is suppressed for Android, but the
test has since been moved to unittests/Thread.SelfJoin. Move the
suppression to unittests.status.

unittests/ThreadLocalStorageTest.DoTest fails on older Android devices
as it assumes the availability of more TLS slots than many devices
implement. Test a smaller number of slots (32) on Android. Remove old
suppression of test-platform-tls/FastTLS (which no longer exists).

cctest/test-mark-compact/RegressJoinThreadsOnIsolateDeinit can't deal
with shared mappings. Check for 's' instead of '-'.

BUG=v8:3706
LOG=

Review URL: https://codereview.chromium.org/735863003

Cr-Commit-Position: refs/heads/master@{#25492}
Don't double smi-tag the mask used to check read-only / field mode in the dictionary-store-stub on X64

BUG=

Review URL: https://codereview.chromium.org/757673002

Cr-Commit-Position: refs/heads/master@{#25493}
Reduce context disposal gc overhead.

BUG=

Review URL: https://codereview.chromium.org/750963002

Cr-Commit-Position: refs/heads/master@{#25494}