ARM: remove the regexp specific literal pool.

It is replaced by a mov_label_offset(Register, Label*) instruction.

BUG=none
TEST=test/cctest/test-assembler-arm.cc
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/23515007

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16676 ce2b1a6d-e550-0410-aec6-3dcde31c8c00