Need -O1 or better to have these builtins lowered to

Need -O1 or better to have these builtins lowered to
llvm intrinsics in llvm-gcc-4.2.  This is because
get_pointer_alignment bails out: it relies on TER
to compute accurate alignment information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40128 91177308-0d34-0410-b5e6-96231b3b80d8