Change to use VEISD::CMPI/CMPU/CMPF/CMPQ and VEISD::CMOV in combineSelectCC
for better optimization. Support VEISD::CMPI/CMPU in combineTRUNCATE also
to optimize truncate. Remove obsolete lower patterns from VEInstrInfo.td.
Update regression tests also.
Reviewed By: efocht
Differential Revision: https://reviews.llvm.org/D136049