Partial revert of 132882.

Partial revert of 132882.
Dan noted that this would work on the case shown on the commit message. I think
the case that was failing was a bb ending with a redundant conditional jump:

...
jne foo

foo:
...

I was unable to find any such case in the tests or in a debug build of clang,
so I will revert this part of the patch and watch the bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133004 91177308-0d34-0410-b5e6-96231b3b80d8