re PR target/78614 (ICE error: invalid rtl sharing found in the insn (verify_rtx_sharing) gcc/emit-rtl.c:2743)

	PR target/78614
	* rtl.c (copy_rtx): Don't clear used flag here.
	(shallow_copy_rtx_stat): Clear used flag here unless code the rtx
	is shareable.
	* simplify-rtx.c (simplify_replace_fn_rtx): When copying rtx with
	'E' in format, copy all vectors.
	* emit-rtl.c (copy_insn_1): Don't clear used flag here.
	* valtrack.c (cleanup_auto_inc_dec): Likewise.
	* config/rs6000/rs6000.c (rs6000_frame_related): Likewise.

From-SVN: r243194