Simplify. No behavior change.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@171680 91177308-0d34-0410-b5e6-96231b3b80d8
Switch to asking the target machine to add any relevant analysis passses
rather than doing it ourselves. This reflects the API changes in r171681.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@171683 91177308-0d34-0410-b5e6-96231b3b80d8