Revert "Add new HSeqStringGetChar instruction."

This reverts commit r17562 for invalid usage of movw to load string
characters. Will reland with fix.

TBR=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/64333002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17563 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Proper support for deopt_every_n_times option on the x64 and ARM architectures.

R=danno@chromium.org
BUG=

Review URL: https://codereview.chromium.org/62293002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17564 ce2b1a6d-e550-0410-aec6-3dcde31c8c00