Introduce CRT_HAS_128BIT, currently for all __LP64__ platforms.
Use it to enable the various functions for TI mode.

llvm-svn: 201909
diff --git a/compiler-rt/lib/builtins/umodti3.c b/compiler-rt/lib/builtins/umodti3.c
index 8ebe7f0..2ab4dd2 100644
--- a/compiler-rt/lib/builtins/umodti3.c
+++ b/compiler-rt/lib/builtins/umodti3.c
@@ -14,7 +14,7 @@
 
 #include "int_lib.h"
 
-#if __x86_64
+#ifdef CRT_HAS_128BIT
 
 tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);
 
@@ -28,4 +28,4 @@
     return r;
 }
 
-#endif
+#endif /* CRT_HAS_128BIT */