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/lshrti3.c b/lib/lshrti3.c
index a284687..3272c9c 100644
--- a/lib/lshrti3.c
+++ b/lib/lshrti3.c
@@ -29,17 +29,17 @@
     input.all = a;
     if (b & bits_in_dword)  /* bits_in_dword <= b < bits_in_tword */
     {
-        result.high = 0;
-        result.low = input.high >> (b - bits_in_dword);
+        result.s.high = 0;
+        result.s.low = input.s.high >> (b - bits_in_dword);
     }
     else  /* 0 <= b < bits_in_dword */
     {
         if (b == 0)
             return a;
-        result.high  = input.high >> b;
-        result.low = (input.high << (bits_in_dword - b)) | (input.low >> b);
+        result.s.high  = input.s.high >> b;
+        result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b);
     }
     return result.all;
 }
 
-#endif
+#endif /* __x86_64 */