Make -fconcepts-ts imply -fconcepts.

* c-opts.c (c_common_post_options): -fconcepts-ts implies
	-fconcepts.

From-SVN: r277859

gcc/c-family/ChangeLog

@@ -1,3 +1,8 @@
+2019-11-05  Jason Merrill  <jason@redhat.com>
+
+	* c-opts.c (c_common_post_options): -fconcepts-ts implies
+	-fconcepts.
+
 2019-11-04  Kamlesh Kumar  <kamleshbhalui@gmail.com>
 
 	* c-opts.c (c_common_post_options): Update

gcc/c-family/c-opts.c

@@ -1038,7 +1038,7 @@ c_common_post_options (const char **pfilename)
      to know when concepts are enabled. Note that -fconcepts-ts can
      be used to include additional features, although modified to
      work with the standard.  */
-  if (cxx_dialect >= cxx2a)
+  if (cxx_dialect >= cxx2a || flag_concepts_ts)
     flag_concepts = 1;
   else if (flag_concepts)
     /* For -std=c++17 -fconcepts, imply -fconcepts-ts.  */

gcc/testsuite/g++.dg/concepts/fn7.C

@@ -1,5 +1,5 @@
 // { dg-do link { target c++14 } }
-// { dg-options "-fconcepts" }
+// { dg-options "-fconcepts-ts" }
 
 void f() requires true { }