Report scripts and libraries searched for ld --trace

Report scripts and libraries searched for ld --trace

The idea of this change is to make -t output useful for users wanting
to package all the object files involved in linking for a bug report.

Something like the following should do the trick.
gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
tar cJf test.tar.xz `cat files`

	* ldlang.c (load_symbols): When -t, print file names for script
	files and archives.
	* ldmain.c (trace_files): Make an int.
	(add_archive_element): Print archive elements only with multiple
	-t options, or when archive is thin.
	* ldmain.h (trace_files): Update.
	* ldmisc.c (vfinfo): Don't print both original path and path in
	sysroot.
	* lexsup.c (parse_args <t>): Increment trace_files.