* final.c (last_columnnum, override_columnnum): New variables.
	(final_start_function): Set last_columnnum, pass it to begin_prologue
	hook and pass 0 to dwarf2out_begin_prologue.
	(final_scan_insn): Update override_columnnum.  Pass last_columnnum
	to source_line debug hook.
	(notice_source_line): Compute last_columnnum and for debug_column_info
	return true on column changes.
	* debug.h (struct gcc_debug_hooks): Add column argument to
	source_line and begin_prologue hooks.
	(debug_nothing_int_charstar_int_bool): Remove prototype.
	(debug_nothing_int_int_charstar,
	debug_nothing_int_int_charstar_int_bool): New prototypes.
	(dwarf2out_begin_prologue): Add column argument.
	* debug.c (do_nothing_debug_hooks): Adjust source_line and
	begin_prologue hooks.
	(debug_nothing_int_charstar_int_bool): Remove.
	(debug_nothing_int_int_charstar,
	debug_nothing_int_int_charstar_int_bool): New functions.
	* dwarf2out.c (dwarf2out_begin_prologue): Add column argument, pass it
	through to dwarf2out_source_line.
	(dwarf2_lineno_debug_hooks): Adjust begin_prologue hook.
	(dwarf2out_source_line): Add column argument, emit it if requested.
	* sdbout.c (sdbout_source_line, sdbout_begin_prologue): Add column
	arguments.
	* xcoffout.h (xcoffout_begin_prologue, xcoffout_source_line): Likewise.
	* xcoffout.c (xcoffout_begin_prologue, xcoffout_source_line): Likewise.
	* vmsdbgout.c (vmsdbgout_begin_prologue): Add column argument, pass it
	through to dwarf2out_begin_prologue.
	(vmsdbgout_source_line): Add column argument, pass it through to
	dwarf2out_source_line.
	* dbxout.c (dbxout_begin_prologue): Add column argument, adjust
	dbxout_source_line caller.
	(dbxout_source_line): Add column argument.

From-SVN: r245564