TSan: Move definition of AtomicOps_x86CPUFeatureStruct into v8::internal namespace

This matches other atomicops_internals_* files.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/21534002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16019 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Use test(reg, imm) when the operand is a register on ia32

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/21521002

Patch from Weiliang Lin <weiliang.lin2@gmail.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16020 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Avoid redundant smi check for Math.abs

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/21180004

Patch from Weiliang Lin <weiliang.lin2@gmail.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16021 ce2b1a6d-e550-0410-aec6-3dcde31c8c00