PR target/65689
	* genpreds.c (struct constraint_data): Add maybe_allows_reg and
	maybe_allows_mem bitfields.
	(maybe_allows_none_start, maybe_allows_none_end,
	maybe_allows_reg_start, maybe_allows_reg_end, maybe_allows_mem_start,
	maybe_allows_mem_end): New variables.
	(compute_maybe_allows): New function.
	(add_constraint): Use it to initialize maybe_allows_reg and
	maybe_allows_mem fields.
	(choose_enum_order): Sort the non-is_register/is_const_int/is_memory/
	is_address constraints such that those that allow neither mem nor
	reg come first, then those that only allow reg but not mem, then
	those that only allow mem but not reg, then the rest.
	(write_allows_reg_mem_function): New function.
	(write_tm_preds_h): Call it.
	* stmt.c (parse_output_constraint, parse_input_constraint): Use
	the generated insn_extra_constraint_allows_reg_mem function
	instead of always setting *allows_reg = true; *allows_mem = true;
	for unknown extra constraints.

	* gcc.target/aarch64/c-output-template-4.c: New test.

From-SVN: r222186