* pt.c (maybe_instantiate_noexcept): For function templates, use their
	template result (function decl).  Don't set up local specializations.
	Temporarily turn on processing_template_decl.  Update the template type
	too.

	* g++.dg/cpp0x/noexcept38.C: New test.
	* g++.dg/cpp0x/noexcept39.C: New test.
	* g++.dg/cpp1z/noexcept-type21.C: New test.

From-SVN: r270005