PR c++/92531 - ICE with noexcept(lambda).

This was failing because uses_template_parms didn't recognize LAMBDA_EXPR as
a kind of expression.  Instead of trying to enumerate all the different
varieties of expression and then aborting if what's left isn't
error_mark_node, let's handle error_mark_node and then assume anything else
is an expression.

	* pt.c (uses_template_parms): Don't try to enumerate all the
	expression cases.

gcc/cp/ChangeLog

+2020-01-17  Jason Merrill  <jason@redhat.com>
+
+	PR c++/92531 - ICE with noexcept(lambda).
+	* pt.c (uses_template_parms): Don't try to enumerate all the
+	expression cases.
+
 2020-01-17  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/93228

gcc/cp/pt.c

@@ -10537,22 +10537,11 @@ uses_template_parms (tree t)
 		   || uses_template_parms (TREE_CHAIN (t)));
   else if (TREE_CODE (t) == TYPE_DECL)
     dependent_p = dependent_type_p (TREE_TYPE (t));
-  else if (DECL_P (t)
-	   || EXPR_P (t)
-	   || TREE_CODE (t) == TEMPLATE_PARM_INDEX
-	   || TREE_CODE (t) == OVERLOAD
-	   || BASELINK_P (t)
-	   || identifier_p (t)
-	   || TREE_CODE (t) == TRAIT_EXPR
-	   || TREE_CODE (t) == CONSTRUCTOR
-	   || CONSTANT_CLASS_P (t))
+  else if (t == error_mark_node)
+    dependent_p = false;
+  else
     dependent_p = (type_dependent_expression_p (t)
 		   || value_dependent_expression_p (t));
-  else
-    {
-      gcc_assert (t == error_mark_node);
-      dependent_p = false;
-    }
 
   processing_template_decl = saved_processing_template_decl;
 

gcc/testsuite/g++.dg/cpp1z/constexpr-lambda25.C

+// PR c++/92531
+// { dg-do compile { target c++17 } }
+
+template <typename XK>
+void ky () noexcept ([]{}); // IFNDR
+// Optional error: void(*)() to bool conv in converted constant expression
+// { dg-prune-output "converted constant expression" }