[CodeGenPrepare] Test case for the promotions that bypass the
profitability check due to some other checks in the addressing
mode matcher. I.e., test case for commit r201121.

<rdar://problem/16020230>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201132 91177308-0d34-0410-b5e6-96231b3b80d8