Note to self: verified the compile on pdp11-aout
gcc/
* auto-inc-dec.c (struct inc_insn): Strengthen field "insn" from
rtx to rtx_insn *.
(struct mem_insn): Likewise for field "insn".
(reg_next_use): Strengthen from rtx * to rtx_insn **.
(reg_next_inc_use): Likewise.
(reg_next_def): Likewise.
(move_dead_notes): Strengthen params "to_insn" and "from_insn"
from rtx to rtx_insn *.
(move_insn_before): Likewise for param "next_insn" and local "insns".
(attempt_change): Likewise for local "mov_insn".
(try_merge): Likewise for param "last_insn".
(get_next_ref): Likewise for return type and local "insn".
Strengthen param "next_array" from rtx * to rtx_insn **.
(parse_add_or_inc): Strengthen param "insn" from rtx to
rtx_insn *.
(find_inc): Likewise for locals "insn" and "other_insn" (three of
the latter).
(merge_in_block): Likewise for locals "insn", "curr",
"other_insn".
(pass_inc_dec::execute): Update allocations of the arrays to
reflect the stronger types.