[InstSimplify] change tests to 'fast' to reflect current folds

The diff to use 'reassoc' is part of D43160; it should not have
been made with rL324961. Reverting that part here, so we'll
see the intended diff with the code change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324963 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed