* fwprop.c (try_fwprop_subst): Use validate_unshare_change.
	* postreload.c (reload_cse_simplify_set): Instead of copying the rtx
	early use validate_unshare_change.
	(reload_combine): Likewise.
	* recog.c (change_t): New field unshare.
	(validate_change_1): Rename from validate_change; add argument unshare.
	(validate_change): Turn into wrapper of validate_change_1; update
	prototype for bools.
	(validate_unshare_change): New.
	(confirm_change_group): Unshare changes if asked for; avoid unnecesary
	calls of df_insn_rescan.
	* recog.h (validate_change): Replace ints by bools.
	(validate_unshare_change): Declare.

From-SVN: r126050