PR c++/48945
	* decl.c (grokdeclarator): Don't add set const function-cv-qual
	for constexpr fns to memfn_quals, just add it to the type.
	(revert_static_member_fn): Don't complain about quals.
	(check_static_quals): New.
	(grokfndecl): Call it.
	(start_preparsed_function): Don't call revert_static_member_fn.

From-SVN: r174007