ARM: clean-up some stub call sequences.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/203263016

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20089 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
ElementsAccessor::SetLength() handlified.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/204603003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20090 ce2b1a6d-e550-0410-aec6-3dcde31c8c00