Convert opaque type when struct definition is seen.

llvm-svn: 45287
diff --git a/clang/test/CodeGen/OpaqueStruct.c b/clang/test/CodeGen/OpaqueStruct.c
new file mode 100644
index 0000000..ecf81fa
--- /dev/null
+++ b/clang/test/CodeGen/OpaqueStruct.c
@@ -0,0 +1,12 @@
+// RUN: clang %s -emit-llvm
+typedef struct a b;
+
+b* x;
+
+struct a {
+  b* p;
+};
+
+void f() {
+  b* z = x->p;
+}