Version 4.3.61.6 (cherry-pick)

Merged 3cb9f132
Merged ffe886de

Layout descriptor must be trimmed when corresponding descriptors array is trimmed to stay in sync.

Support for typed arrays added to Heap::RightTrimFixedArray().

BUG=chromium:470804,chromium:472513
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1075233002

Cr-Commit-Position: refs/branch-heads/4.3@{#9}
Cr-Branched-From: f5c0a23a-refs/heads/4.3.61@{#1}
Cr-Branched-From: 0a7d4f49-refs/heads/master@{#27508}