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/clzdi2.c b/compiler-rt/lib/clzdi2.c
index 34d4362..ea95396 100644
--- a/compiler-rt/lib/clzdi2.c
+++ b/compiler-rt/lib/clzdi2.c
@@ -23,7 +23,7 @@
 {
     dwords x;
     x.all = a;
-    const si_int f = -(x.high == 0);
-    return __builtin_clz((x.high & ~f) | (x.low & f)) +
+    const si_int f = -(x.s.high == 0);
+    return __builtin_clz((x.s.high & ~f) | (x.s.low & f)) +
            (f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
 }