Revert r141854 because it was causing failures:

http://lab.llvm.org:8011/builders/llvm-x86_64-linux/builds/101

--- Reverse-merging r141854 into '.':
U    test/MC/Disassembler/X86/x86-32.txt
U    test/MC/Disassembler/X86/simple-tests.txt
D    test/CodeGen/X86/bmi.ll
U    lib/Target/X86/X86InstrInfo.td
U    lib/Target/X86/X86ISelLowering.cpp
U    lib/Target/X86/X86.td
U    lib/Target/X86/X86Subtarget.h

llvm-svn: 141857