[lit] Remove some done TODOs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188502 91177308-0d34-0410-b5e6-96231b3b80d8
[tests] Fix refacto in r187764 that effectively disabled SimplifyCFG tests. :(

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188503 91177308-0d34-0410-b5e6-96231b3b80d8