br i1 undef
This PR removes tests with `br i1 undef` under `llvm/tests/Transforms/ObjCARC, Reassociate, SCCP, SLPVectorizer...`. After this PR, I'll continue to fix tests under `llvm/tests/CodeGen`, which has more UB tests than `llvm/tests/Transforms`.
select (A &/| B), T, F
select B, T, F
nuw
nsw
mul
va_list