re PR c++/22252 (pragma interface/implementation still break synthesized methods)

	PR c++/22252
	* decl.c (start_preparsed_function): Do not pay attention to
	#pragma interface for implicitly-defined methods.
	* decl2.c (cp_finish_file): Do not complain about uses of inline
	functions that have bodies, even if we decided not to emit the
	body in this translation unit.
	* semantics.c (note_decl_for_pch): Do not mess with linkage.
	(expand_or_defer_fn): Make inline, non-template functions COMDAT
	at this point.

	PR c++/22252
	* g++.dg/ext/interface1.C: New test.
	* g++.dg/ext/interface1.h: Likewise.
	* g++.dg/ext/interface1a.cc: Likewise.

From-SVN: r104103