X86: Don't generate 64-bit movd after cmpneqsd in 32-bit mode (PR19059)

This fixes the bug where we would bitcast the 64-bit floating point result
of cmpneqsd to a 64-bit integer even on 32-bit targets.

Differential Revision: http://llvm-reviews.chandlerc.com/D3009

llvm-svn: 203581