PR c++/92078

gcc/cp/
	* pt.c (maybe_new_partial_specialization): Apply access to newly
	created partial specializations. Update comment style.

gcc/testsuite/
	* g++.dg/cpp2a/concepts-pr92078.C: New.
  * g++.dg/cpp2a/concepts-requires18.C: Update diagnostics.

From-SVN: r278450