fix a bogus assertion exposed by a recent change: packing the
struct may cause it to shrink more than one byte.  Before
my recent changes we compiled the new test into:

%0 = type { [6 x i8] }
@x = global %0 { [6 x i8] undef }, align 2        ; <%0*> [#uses=0]

which is obviously bogus.  Now we compile it into:

%0 = type <{ i32, i8, i8 }>
@x = global %0 zeroinitializer, align 2           ; <%0*> [#uses=0]

Where the last byte only is tail padding.

llvm-svn: 101536
diff --git a/clang/test/CodeGen/decl.c b/clang/test/CodeGen/decl.c
index 8bbeb24..7ffb700 100644
--- a/clang/test/CodeGen/decl.c
+++ b/clang/test/CodeGen/decl.c
@@ -84,3 +84,8 @@
   {4},
 };
 
+// rdar://7872531
+#pragma pack(push, 2)
+struct test8s { int f0; char f1; } test8g = {};
+
+