Feature-test macro for P0522R0, matching of template template arguments.

	* c-cppbuiltin.c (c_cpp_builtins): Define
	__cpp_template_template_args.

From-SVN: r243896

gcc/c-family/ChangeLog

+2016-12-22  Jason Merrill  <jason@redhat.com>
+
+	Implement P0522R0, matching of template template arguments.
+	* c-cppbuiltin.c (c_cpp_builtins): Define
+	__cpp_template_template_args.
+
 2016-12-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR bootstrap/78817

gcc/c-family/c-cppbuiltin.c

@@ -985,6 +985,8 @@ c_cpp_builtins (cpp_reader *pfile)
 	  cpp_define_formatted (pfile, "__STDCPP_DEFAULT_NEW_ALIGNMENT__=%d",
 				aligned_new_threshold);
 	}
+      if (flag_new_ttp)
+	cpp_define (pfile, "__cpp_template_template_args=201611");
     }
   /* Note that we define this for C as well, so that we know if
      __attribute__((cleanup)) will interface with EH.  */

gcc/testsuite/g++.dg/cpp1z/feat-cxx1z.C

@@ -398,6 +398,12 @@
 #  error "__cpp_structured_bindings != 201606"
 #endif
 
+#ifndef __cpp_template_template_args
+#  error "__cpp_template_template_args"
+#elif __cpp_template_template_args != 201611
+#  error "__cpp_template_template_args != 201611"
+#endif
+
 #ifdef __has_cpp_attribute
 
 #  if ! __has_cpp_attribute(maybe_unused)