The layout of fixed typed array base is then capable of handling
external typed arrays as well. In a follow-up CL, I'll delete external
typed arrays, and use fixed typed array base instead

BUG=v8:3996
R=jarin@chromium.org,mstarzinger@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/1248483007

Cr-Commit-Position: refs/heads/master@{#29786}

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/1041743002

Cr-Commit-Position: refs/heads/master@{#27501}

Inspired by a patch by Slava Chigrin <vchigrin@yandex-team.ru>

R=jkummerow@chromium.org, vchigrin@yandex-team.ru

Review URL: https://codereview.chromium.org/441983002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22896 ce2b1a6d-e550-0410-aec6-3dcde31c8c00