re PR debug/77985 (DW_AT_comp_dir is omitted when filename is absolute and the file does not contain a specific typedef)

2016-10-24  Ximin Luo  <infinity0@pwned.gg>

	PR debug/77985
	* dwarf2out.c (file_table_relative_p): Remove.
	(gen_compile_unit_die, dwarf2out_early_finish): Emit DW_AT_comp_dir
	also for absolute paths.
	* doc/tm.texi: Update.
	* doc/tm.texi.in (SDB and DWARF) <TARGET_FORCE_AT_COMP_DIR>: Remove.
	* target.def (force_at_comp_dir): Remove hook.
	* config/darwin.h (TARGET_FORCE_AT_COMP_DIR): Remove define.

From-SVN: r241473