Fix compilation after SVN r368476

That revision broke compilation with this error:

lib/builtins/fixunsxfdi.c:13:2: error: unterminated conditional directive
 #if !_ARCH_PPC

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@368480 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed