re PR debug/66668 (FAIL: gcc.dg/debug/dwarf2/stacked-qualified-types-3.c scan-assembl...

re PR debug/66668 (FAIL: gcc.dg/debug/dwarf2/stacked-qualified-types-3.c scan-assembler-times DIE \\([^\n]*\\) DW_TAG_(?:const|volatile|atomic|restrict)_type 8)

	PR debug/66668
	* dwarf2out.c (add_child_die_after): New function.
	(dwarf_qual_info_t): New type.
	(dwarf_qual_info): New variable.
	(qualified_die_p): New function.
	(modified_type_die): For -fdebug-types-section, ensure
	canonical order of qualifiers.  Put qualified DIEs adjacent
	to the corresponding non-qualified type DIE and search there
	for existing qualified DIEs.

From-SVN: r232719