Revert r182937 and r182877.

r182877 broke MCJIT tests on ARM and r182937 was working around another failure
by r182877.

This should make the ARM bots green.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182960 91177308-0d34-0410-b5e6-96231b3b80d8