On Wed, 2014-08-06 at 13:20 -0400, David Malcolm wrote:
> gcc/
> 	* basic-block.h (create_basic_block_structure): Strengthen third
> 	param "bb_note" from rtx to rtx_note *.
> 	* rtl.h (emit_note_before): Strengthen return type from rtx to
> 	rtx_note *.
> 	(emit_note_after): Likewise.
> 	(emit_note): Likewise.
> 	(emit_note_copy): Likewise.  Also, strengthen param similarly.
> 	* function.h (struct rtl_data): Strengthen field
> 	"x_stack_check_probe_note" from rtx to rtx_note *.
> 
> 	* cfgexpand.c (expand_gimple_basic_block): Strengthen local "note"
> 	from rtx to rtx_note *.
> 	* cfgrtl.c (create_basic_block_structure): Strengthen third param
> 	"bb_note" from rtx to rtx_note *.
> 	(duplicate_insn_chain): Likewise for local "last".  Add a checked cast
> 	when calling emit_note_copy.
> 	* emit-rtl.c (make_note_raw): Strengthen return type from rtx to
> 	rtx_note *.
> 	(emit_note_after): Likewise.
> 	(emit_note_before): Likewise.
> 	(emit_note_copy): Likewise.  Also, strengthen param similarly.
> 	(emit_note): Likewise.
> 	* except.c (convert_to_eh_region_ranges): Strengthen local "note"
> 	from rtx to rtx_note *.
> 	* final.c (change_scope): Likewise.
> 	(reemit_insn_block_notes): Likewise, for both locals named "note".
> 	Also, strengthen local "insn" from rtx to rtx_insn *.
> 	* haifa-sched.c (sched_extend_bb): Strengthen local "note" from
> 	rtx to rtx_note *.
> 	* reg-stack.c (compensate_edge): Likewise for local "after". Also,
> 	strengthen local "seq" from rtx to rtx_insn *.
> 	* reload1.c (reload_as_needed): Strengthen local "marker" from rtx
> 	to rtx_note *.
> 	* sel-sched-ir.c (bb_note_pool): Strengthen from rtx_vec_t to
> 	vec<rtx_note *>.
> 	(get_bb_note_from_pool): Strengthen return type from rtx to
> 	rtx_note *.
> 	(sel_create_basic_block): Strengthen local "new_bb_note" from
> 	insn_t to rtx_note *.
> 	* var-tracking.c (emit_note_insn_var_location): Strengthen local
> 	"note" from rtx to rtx_note *.
> 	(emit_notes_in_bb): Likewise.

I believe this is covered by Jeff's blanket approval here:
https://gcc.gnu.org/ml/gcc-patches/2014-08/msg01337.html

Successfully bootstrapped&regrtested on x86_64-unknown-linux-gnu
(Fedora 20) albeit in combination with patches 31-39, and verified that
it builds standalone for 7 targets. 

Committed to trunk as r214192.

This required some additional changes relative to what I originally
posted, specifically to emit_note_eh_region_end (since
emit_note_eh_region_end was added in r212171).  I'm attaching what I
actually committed.