[X86] Improve EmitLoweredSelect for contiguous CMOV pseudo instructions.

This change improves EmitLoweredSelect() so that multiple contiguous CMOV pseudo
instructions with the same (or exactly opposite) conditions get lowered using a single
new basic-block. This eliminates unnecessary extra basic-blocks (and CFG merge points)
when contiguous CMOVs are being lowered.

Patch by: kevin.b.smith@intel.com
Differential Revision: http://reviews.llvm.org/D11428


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244202 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed