re PR middle-end/43631 (var-tracking inserts notes with non-NULL BLOCK_FOR_INSN in between basic blocks)

	PR middle-end/43631
	PR bootstrap/55615
	* var-tracking.c (emit_note_insn_var_location): If insn is followed
	by BARRIER, put note after the BARRIER.
	(next_non_note_insn_var_location): Skip over BARRIERs.
	(emit_notes_in_bb): If call is followed by BARRIER, put note after
	the BARRIER.

	* g++.dg/other/pr43631.C: New test.

From-SVN: r194392