Remove a recently redundant transform from X86ISelLowering.

X86ISelLowering has support to treat:
(icmp ne (and (xor %flags, -1), (shl 1, flag)), 0)

as if it were actually:
(icmp eq (and %flags, (shl 1, flag)), 0)

However, r179386 has code at the InstCombine level to handle this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181145 91177308-0d34-0410-b5e6-96231b3b80d8