Recommit "[X86] Use X86ISD::SUB instead of X86ISD::CMP in some places."

This time with correct types for the data result from the SUB.

Original commit message:

Our normal lowering for ISD::SETCC uses X86ISD::SUB to enable
CSE unless the RHS is 0. optimizeCompareInstr called by the peephole
pass can turn subs with unused results into cmps to clean this up.

This commit makes other places that create X86ISD::CMP have the
same behavior.