MIPS: Cleanup in stub-cache.cc; remove unused ArrayLength store ICs.

Port r22805 (d6b2885f)

BUG=
R=dusan.milosavljevic@imgtec.com

Review URL: https://codereview.chromium.org/439733003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22824 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
[Auto-roll] Bump up version to 3.28.55.0

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/436253003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22825 ce2b1a6d-e550-0410-aec6-3dcde31c8c00