Revert "ARM: Do not set FPSCR when converting to clamped uint8"

This reverts commit r20676.

TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/233013005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20678 ce2b1a6d-e550-0410-aec6-3dcde31c8c00