* debug.h (struct gcc_debug_hooks): Add IMPLICIT argument
	to imported_module_or_decl hook.
	(debug_nothing_tree_tree_tree_bool): Remove.
	(debug_nothing_tree_tree_tree_bool_bool): New declaration.
	* debug.c (do_nothing_debug_hooks): Use
	debug_nothing_tree_tree_tree_bool_bool instead of
	debug_nothing_tree_tree_tree_bool.
	* vmsdbgout.c (vmsdbg_debug_hooks): Likewise.
	* dbxout.c (dbx_debug_hooks, xcoff_debug_hooks): Likewise.
	* sdbout.c (sdb_debug_hooks): Likewise.
	* dwarf2out.c (dwarf2_lineno_debug_hooks): Likewise.
	(gen_namespace_die): Add DW_AT_export_symbols attribute if
	langhook wants it.
	(dwarf2out_imported_module_or_decl): Add IMPLICIT argument,
	if true, -gdwarf-5 and decl will have DW_AT_export_symbols
	attribute, don't add anything.
cp/
	* cp-objcp-common.c (cp_decl_dwarf_attribute): Handle
	DW_AT_export_symbols.
	* name-lookup.c (emit_debug_info_using_namespace): Add IMPLICIT
	argument, pass it through to the debug hook.
	(finish_namespace_using_directive): Adjust
	emit_debug_info_using_namespace caller.
	(push_namespace): Likewise.  Call it after setting
	DECL_NAMESPACE_INLINE_P.
	(cp_emit_debug_info_for_using): Pass false as new argument to
	the imported_module_or_decl debug hook.
fortran/
	* trans-decl.c (gfc_trans_use_stmts): Pass false as new argument to
	the imported_module_or_decl debug hook.
ada/
	* gcc-interface/utils.c (gnat_write_global_declarations): Pass false
	as new argument to the imported_module_or_decl debug hook.
testsuite/
	* g++.dg/debug/dwarf2/inline-ns-1.C: New test.
	* g++.dg/debug/dwarf2/inline-ns-2.C: New test.

From-SVN: r250713