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


	PR middle-end/43631
	* emit-rtl.c (make_note_raw): New function.
	(link_insn_into_chain): New static inline function.
	(add_insn): Use it.
	(add_insn_before, add_insn_after): Factor insn chain linking code...
	(add_insn_before_nobb, add_insn_after_nobb): ...here, new functions
	using link_insn_into_chain.
	(note_outside_basic_block_p): New helper function for emit_note_after
	and emit_note_before.
	(emit_note_after): Use nobb variant of add_insn_after if the note
	should not be contained in a basic block.
	(emit_note_before): Use nobb variant of add_insn_before if the note
	should not be contained in a basic block.
	(emit_note_copy): Use make_note_raw.
	(emit_note): Likewise.
	* bb-reorder.c (insert_section_boundary_note): Remove hack to set
	BLOCK_FOR_INSN to NULL manually for NOTE_INSN_SWITCH_TEXT_SECTIONS.
	* jump.c (cleanup_barriers): Use reorder_insns_nobb to avoid making
	the moved barrier the tail of the basic block it follows.
	* var-tracking.c (pass_variable_tracking): Add TODO_verify_flow.

From-SVN: r197994