This revision adds support for canonicalizing the following:
cond_br %cond, ^bb1(A, ..., N), ^bb1(A, ..., N) br ^bb1(A, ..., N)
If the operands to the successor are different and the cond_br is the only predecessor, we emit selects for the branch operands.
cond_br %cond, ^bb1(A), ^bb1(B) %select = select %cond, A, B br ^bb1(%select)
Depends On D78681