another expr/decl ambiguity test

From-SVN: r21828

gcc/testsuite/g++.old-deja/g++.brendan/parse6.C

@@ -0,0 +1,13 @@
+// Build don't link: 
+
+// this is marked as an expected error because it evidences an
+// ambiguity in the grammar between expressions and declarations.
+// when the parser's been cleaned up or rewritten, the error
+// marker can go away, since it'll no longer occur.
+
+class A { };
+
+main()  {
+  A a = a;
+  A b(b); // ERROR - 
+}