* flags.h (flag_dump_rtl_in_asm): Declare.
	* toplev.c (flag_dump_rtl_in_asm): Define.
	(decode_d_option): Set flag_dump_rtl_in_asm and flag_print_asm_name
	if -dP is specified.
	* rtl.h (print_rtx_head): Declare.
	* print-rtl.c (print_rtx_head): Define.
	(print_rtx): Print the string pointed to by print_rtx_head
	at beginning of each dump line.
	(print_rtl): Likewise.
	(print_rtl_single): Likewise.
	* final.c (final_scan_insn): Dump the insn in the assembly
	file for debugging.
	* gcc.1: Document -dP option.
	* invoke.texi (Debugging Options): Likewise.

From-SVN: r36394