Refactor to remove un-named struct gnu extension usage. Now ISO C89 and C99 compliant. Comment trailing endifs

llvm-svn: 78537
diff --git a/compiler-rt/lib/clzti2.c b/compiler-rt/lib/clzti2.c
index acdf479..eb05e2e 100644
--- a/compiler-rt/lib/clzti2.c
+++ b/compiler-rt/lib/clzti2.c
@@ -30,4 +30,4 @@
            ((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT)));
 }
 
-#endif
+#endif /* __x86_64 */