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

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@78537 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/fixunsdfdi.c b/lib/fixunsdfdi.c
index 4d5dcfe..bdcee13 100644
--- a/lib/fixunsdfdi.c
+++ b/lib/fixunsdfdi.c
@@ -31,12 +31,12 @@
 {
     double_bits fb;
     fb.f = a;
-    int e = ((fb.u.high & 0x7FF00000) >> 20) - 1023;
-    if (e < 0 || (fb.u.high & 0x80000000))
+    int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
+    if (e < 0 || (fb.u.s.high & 0x80000000))
         return 0;
     udwords r;
-    r.high = (fb.u.high & 0x000FFFFF) | 0x00100000;
-    r.low = fb.u.low;
+    r.s.high = (fb.u.s.high & 0x000FFFFF) | 0x00100000;
+    r.s.low = fb.u.s.low;
     if (e > 52)
         r.all <<= (e - 52);
     else