Don't use fast isel on this test.

This fixes the test on ARM. Looks like it was broken by r182877. Not
sure if this is a bug on fast isel on ARM, but this should help fix
the ARM bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182937 91177308-0d34-0410-b5e6-96231b3b80d8