Fixes the self-host fail. Note that this commit activates dominator
analysis in the combiner by default (like the original commit did).
llvm-svn: 222590
The icmp-select-icmp optimization targets select-icmp.eq
only. This is now ensured by testing the branch predicate
explictly. This commit also includes the test case for pr21199.
llvm-svn: 219282