[PR63240] generate debug info for defaulted member functions

[PR63240] generate debug info for defaulted member functions

This implements <http://dwarfstd.org/ShowIssue.php?issue=141215.3>, a
proposal already accepted for inclusion in DWARF-5, but using
DW_AT_GNU_defaulted instead of DW_AT_defaulted as the attribute name,
because the attribute id for DW_AT_defaulted is not yet publicly
available.

for  include/ChangeLog

	PR debug/63240
	* dwarf2.def (DW_AT_deleted, DW_AT_defaulted): New.
	* dwarf2.h (enu dwarf_defaulted_attribute): New.

for  gcc/ChangeLog

	PR debug/63240
	* langhooks-def.h
	(LANG_HOOKS_FUNCTION_DECL_EXPLICIT_P): Const_tree-ify.
	(LANG_HOOKS_FUNCTION_DECL_DELETED_P): Likewise.
	(LANG_HOOKS_FUNCTION_DECL_DEFAULTED): Set default.
	(LANG_HOOKS_DECLS): Add it.
	* langhooks.h (struct lang_hooks_for_decls): Add
	function_decl_defaulted.  Const_tree-ify
	function_decl_explicit_p and function_decl_deleted_p.
	* dwarf2out.c (gen_subprogram_die): Add DW_AT_defaulted
	attribute.  Add DW_AT_deleted instead of DW_AT_GNU_deleted,
	also at strict DWARF v5.

for  gcc/cp/ChangeLog

	PR debug/63240
	* cp-objcp-common.c (cp_function_decl_defaulted): New.
	(cp_function_decl_explicit_p): Const_tree-ify.
	(cp_function_decl_deleted_p): Likewise.
	* cp-objcp-common.h (cp_function_decl_defaulted): Declare.
	(cp_function_decl_explicit_p): Const_tree-ify.
	(cp_function_decl_deleted_p): Likewise.
	(LANG_HOOKS_FUNCTION_DECL_DEFAULTED): Redefine.

for  gcc/testsuite/ChangeLog

	PR debug/63240
	* g++.dg/debug/dwarf2/defaulted-member-function-1.C: New.
	* g++.dg/debug/dwarf2/defaulted-member-function-2.C: New.
	* g++.dg/debug/dwarf2/defaulted-member-function-3.C: New.
	* g++.dg/debug/dwarf2/deleted-member-function.C: Expect
	DW_AT_deleted.

From-SVN: r239403