Disable the inclusion of logical input files in the assembler listing output unless...

Disable the inclusion of logical input files in the assembler listing output unless high level source listing has been enabled.

	PR 21977
	* listing.c (listing_newline): Use the name of the current
	physical input file, rather than the current logical input file,
	unless including high level source in the listing.
	* input-scrub.c (as_where_physical): New function.  Returns the
	name of the current physical input file.
	* as.h: Add prototype for as_where_physical.