Mangle anonymous structs/unions correctly. Fixes PR5139.

llvm-svn: 83448
diff --git a/clang/test/CodeGenCXX/mangle.cpp b/clang/test/CodeGenCXX/mangle.cpp
index a881a710..2ffbae7 100644
--- a/clang/test/CodeGenCXX/mangle.cpp
+++ b/clang/test/CodeGenCXX/mangle.cpp
@@ -207,3 +207,17 @@
 // CHECK: @extern_f
 void extern_f(void) { }
 
+struct S7 {
+  struct S { S(); };
+  
+  struct {
+    S s;
+  } a;
+};
+
+// PR5139
+// CHECK: @_ZN2S7C1Ev
+// CHECK: @_ZN2S7C2Ev
+// CHECK: @"_ZN2S73$_0C1Ev"
+S7::S7() {}
+