Dynamic tls access model will be lowered to MI which clobbers CTR in
the loop in ISEL(ADDItlsgdLADDR) and post-isel CTR loop pass will revert
the loop to a normal compare + branch form.
So no need to add this clobber check in hardware loop insertion pass now.
Reviewed By: nemanjai
Differential revision: https://reviews.llvm.org/D140367