c++: Fix template parm with dependent type in concepts.

While looking at PR94186 I also noticed this regression; if a non-type
template parameter uses a type parameter in its type, we need to map both
template parameters.

gcc/cp/ChangeLog
2020-03-24  Jason Merrill  <jason@redhat.com>

	* pt.c (any_template_parm_r): Look into the type of a non-type
	template parm.

gcc/cp/ChangeLog

 2020-03-24  Jason Merrill  <jason@redhat.com>
 
+	* pt.c (any_template_parm_r): Look into the type of a non-type
+	template parm.
+
+2020-03-24  Jason Merrill  <jason@redhat.com>
+
 	* cp-tree.h (cp_expr): When constructing from an expr and a
 	location, call protected_set_expr_location.
 

gcc/cp/pt.c

@@ -10431,6 +10431,7 @@ any_template_parm_r (tree t, void *data)
       WALK_SUBTREE (TREE_OPERAND (t, 1));
       break;
 
+    case TEMPLATE_PARM_INDEX:
     case PARM_DECL:
       /* A parameter or constraint variable may also depend on a template
 	 parameter without explicitly naming it.  */

gcc/testsuite/g++.dg/cpp2a/concepts-nonbool2.C

+// { dg-do compile { target concepts } }
+
+template<class X, X x>
+concept C = requires {
+    requires x;			// { dg-error "bool" }
+  };
+
+int main() {
+  C<int, 0>;
+  return 0;
+}