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/muloti4.c b/compiler-rt/lib/builtins/muloti4.c
index f58dd07..0aa6f3b 100644
--- a/compiler-rt/lib/builtins/muloti4.c
+++ b/compiler-rt/lib/builtins/muloti4.c
@@ -14,7 +14,7 @@
 
 #include "int_lib.h"
 
-#if __x86_64
+#ifdef CRT_HAS_128BIT
 
 /* Returns: a * b */
 
@@ -59,4 +59,4 @@
     return result;
 }
 
-#endif
+#endif /* CRT_HAS_128BIT */