re PR debug/43540 (ICE: vector VEC(dw_cfi_ref,heap) grow domain error, in output_cfis...

re PR debug/43540 (ICE: vector VEC(dw_cfi_ref,heap) grow domain error, in output_cfis at dwarf2out.c:3346 or OOM-killed)

	PR debug/43540
	* dwarf2out.c (reg_save): For DW_CFA_expression put regnum
	into first operand and location into second.
	(dw_cfi_oprnd1_desc): Return dw_cfi_oprnd_reg_num instead of
	dw_cfi_oprnd_loc for DW_CFA_expression.
	(dw_cfi_oprnd2_desc): Return dw_cfi_oprnd_loc for DW_CFA_expression.
	(output_cfa_loc, output_cfa_loc_raw): For DW_CFA_expression
	assume first argument is regnum and second argument is location.

From-SVN: r157762