Move misplaced x86_32 ABI code

r184166 added an X86_32 function in the middle of the SystemZ code.
The SystemZ port had been added only a couple of weeks earlier and
the original patch probably predated that.

No behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212524 91177308-0d34-0410-b5e6-96231b3b80d8