cppinit.c (init_standard_includes): The returned buffer is already malloc-ed.

	* cppinit.c (init_standard_includes): The returned buffer
	is already malloc-ed.
	* gcc.c (add_prefix): Similarly.
	* prefix.c (translate_name): Update to support clear buffer
	ownership rules.
	(update_path): Similarly.  Be sure to free any newly allocated
	key.  UPDATE_PATH_HOST_CANONICALIZE takes only one argument.
	(tr): New function.
	* prefix.h (update_path): Update prototype and document.
	* config/i386/xm-djgpp.h (UPDATE_PATH_HOST_CANONICALIZE): Clean
	up and update to new buffer ownership rules.
	* doc/gcc.texi (UPDATE_PATH_HOST_CANONICALIZE): Update.

From-SVN: r45043