[X86] Bugfix for rL146415

[yubing]

Summary

[X86] Bugfix for rL146415
modify this testcase for both i386 and amd64

[RKSimon]

rL146415 was committed in 2011 - is this actually being run on 32-bits?

[yubing]

@RKSimon , you're right. After checking https://reviews.llvm.org/rL146415, I found the makefile has disable this testcase for i386.

SingleSource/UnitTests/ms_struct-bitfield-1.c

 #pragma ms_struct off
 
 int main(int argc, char *argv[])
 {
 #pragma unused(argc, argv)
   int sizeof_packoddity = sizeof(PackOddity);
   int offsetof_foo = offsetof(PackOddity, foo);
   int offsetof_pv2 = offsetof(PackOddity, pv2);
+#if defined(__i386)
+        if (sizeof_packoddity != 20)
+         abort();
+        if (offsetof_foo != 4)
+          abort();
+        if (offsetof_pv2 != 16)
+          abort();
+#else
         if (sizeof_packoddity != 40)
          abort();
         if (offsetof_foo != 8)
           abort();
         if (offsetof_pv2 != 32)
           abort();
+#endif
   return 0;
 }