Collect type feedback for power-of-2 right operands in BinaryOps.

Improved --trace-ic output for unary/binary ops a bit on the way. Moved int32_t/uint32_t conversion helpers around.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/15735005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14928 ce2b1a6d-e550-0410-aec6-3dcde31c8c00