Replace one error with inform.

	PR c++/92440
	* pt.c (redeclare_class_template): Use inform
	for the second location.
	PR c++/92440
	* g++.dg/template/pr92440.C: New test.
	* g++.dg/cpp0x/vt-34314.C: Update error to note.
	* g++.dg/template/pr59930-2.C: Likewise.
	* g++.old-deja/g++.pt/redecl1.C: Likewise.

gcc/cp/ChangeLog

+2020-01-28  Martin Liska  <mliska@suse.cz>
+
+	PR c++/92440
+	* pt.c (redeclare_class_template): Use inform
+	for the second location.
+
 2020-01-27  Jason Merrill  <jason@redhat.com>
 
 	PR c++/90966

gcc/cp/pt.c

@@ -6149,7 +6149,7 @@ redeclare_class_template (tree type, tree parms, tree cons)
 		  != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
 	{
 	  error ("template parameter %q+#D", tmpl_parm);
-	  error ("redeclared here as %q#D", parm);
+	  inform (input_location, "redeclared here as %q#D", parm);
 	  return false;
 	}
 

gcc/testsuite/ChangeLog

+2020-01-28  Martin Liska  <mliska@suse.cz>
+
+	PR c++/92440
+	* g++.dg/template/pr92440.C: New test.
+	* g++.dg/cpp0x/vt-34314.C: Update error to note.
+	* g++.dg/template/pr59930-2.C: Likewise.
+	* g++.old-deja/g++.pt/redecl1.C: Likewise.
+
 2020-01-28  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/93418

gcc/testsuite/g++.dg/cpp0x/vt-34314.C

@@ -4,7 +4,7 @@ template<typename Fun, typename... Args> // { dg-error "template parameter" }
 struct call;
 
 template<typename Fun, typename Arg0>
-struct call // { dg-error "redeclared here" }
+struct call // { dg-message "note: redeclared here" }
 {
     template<typename Sig>
     struct result;
@@ -21,7 +21,7 @@ template<typename Fun, int... N> // { dg-error "template parameter" }
 struct call2;
 
 template<typename Fun, int N>
-struct call2 // { dg-error "redeclared here" }
+struct call2 // { dg-message "note: redeclared here" }
 {
     template<typename Sig>
     struct result;
@@ -37,7 +37,7 @@ template<typename Fun, template<typename> class... TT> // { dg-error "template p
 struct call3;
 
 template<typename Fun, template<typename> class TT>
-struct call3 // { dg-error "redeclared here" }
+struct call3 // { dg-message "note: redeclared here" }
 {
     template<typename Sig>
     struct result;

gcc/testsuite/g++.dg/template/pr59930-2.C

@@ -6,7 +6,7 @@ namespace N {
     // Injects N::N
     template < T > friend class N;
     // { dg-error "template parameter" "" { target *-*-* } .-1 }
-    // { dg-error "redeclared"  "" { target *-*-* } .-2 }
+    // { dg-message "note: redeclared"  "" { target *-*-* } .-2 }
   };
 }
 

gcc/testsuite/g++.dg/template/pr92440.C

+// PR c++/92440
+// { dg-do compile }
+
+template <int T> // { dg-error "template parameter" }
+struct S {
+    template <class U>
+    friend struct S;  // { dg-message "note: redeclared here as" }
+};
+
+S<0> s;

gcc/testsuite/g++.dg/template/redecl2.C

@@ -6,4 +6,4 @@
 // non-type template parameter.
 
 template <int i> struct X;	// { dg-error "template parameter" }
-template <int* p> struct X;	// { dg-error "redeclared here" }
+template <int* p> struct X;	// { dg-message "note: redeclared here" }

gcc/testsuite/g++.old-deja/g++.pt/redecl1.C

@@ -16,7 +16,7 @@ template <class T> // { dg-error "template parameter" }
 struct S3;
 
 template <int I>
-struct S3; // { dg-error "redeclared here" } 
+struct S3; // { dg-message "note: redeclared here" } 
 
 template <template <class T> class C>
-struct S3; // { dg-error "redeclared here" } 
+struct S3; // { dg-message "note: redeclared here" }