that the ARM and 16-bit Thumb opcode tables each have comments
preceding them that describe all the codes, and only the codes,
valid in those tables. (32-bit Thumb table is already like this.)
Reorder the lists in all three comments to match the order in
which the codes are implemented.
Remove all forward declarations of static functions. Convert all
function definitions to ISO C format.
(print_insn_arm, print_insn_thumb16, print_insn_thumb32):
Return nothing.
(print_insn_thumb16): Remove unused case 'I'.
(print_insn): Update for changed calling convention of subroutines.
