re PR c++/9336 (ICE in cp_line_of, at cp/error.c:2191)

        PR c++/9336
        * decl2.c (lookup_arg_dependent): Handle error_mark_node.

[[Split portion of a mixed commit.]]

From-SVN: r64322.2

gcc/testsuite/g++.dg/overload/koenig1.C

+// PR c++/9336
+// Bug: The first, invalid call to f caused us to crash on the second,
+// valid call.
+
+namespace N {
+  template <class T> void f (T);
+  struct A;
+}
+
+struct B;
+
+void g ()
+{
+  B *bp;
+  N::A *ap;
+  f (bp);			// { dg-error "undeclared" }
+  f (ap);
+}