(File_Time_Stamp): New procedure.
	(Preserve_Mode): New boolean.
	(Write_Unit): Pass time stamp.
	Implement -p switch (preserve time stamps).

	* gnatcmd.adb (CHOP): Add translation for -p (/PRESERVE).

	* gnatchop.adb: Do usage info for -p switch

	* adaint.h (__gnat_set_file_time_name): New function

	* adaint.c (__gnat_set_file_time_name): Implement

	* adaint.h: Fix typo

From-SVN: r47613