var-tracking.c (unshare_variable): Force initialized to be VAR_INIT_STATUS_INITIALIZED unless flag_var_tracking_uninit.

	* var-tracking.c (unshare_variable): Force initialized to
	be VAR_INIT_STATUS_INITIALIZED unless flag_var_tracking_uninit.
	(set_variable_part): Likewise.
	(struct variable_union_info): Remove pos_src field.
	(vui_vec, vui_allocated): New variables.
	(variable_union): Pass VAR_INIT_STATUS_UNKNOWN to unshare_variable
	unconditionally.  Avoid XCVECNEW/free for every sorting, for dst_l
	== 1 use a simpler sorting algorithm.  Compute pos field right
	away, don't fill in pos_src.  For dst_l == 2 avoid qsort.
	Avoid quadratic comparison if !flag_var_tracking_uninit.
	(variable_canonicalize): Pass VAR_INIT_STATUS_UNKNOWN to
	unshare_variable unconditionally.   
	(dataflow_set_different_2): Removed.
	(dataflow_set_different): Don't traverse second hash table.
	(compute_bb_dataflow): Pass VAR_INIT_STATUS_UNINITIALIZED
	unconditionally to var_reg_set or var_mem_set.
	(emit_notes_in_bb): Likewise.
	(delete_variable_part): Pass VAR_INIT_STATUS_UNKNOWN to
	unshare_variable.
	(emit_note_insn_var_location): Don't set initialized to
	VAR_INIT_STATUS_INITIALIZED early.
	(vt_finalize): Free vui_vec if needed, clear vui_vec and
	vui_allocated.
	* rtl.c (rtx_equal_p): Don't implement on top of rtx_equal_p_cb.

From-SVN: r148852