PR991

PR991
* config/tc-m68k.c (m68k_ip): Test for insn compatiblity using a temporary copy
  of the operands array so that changes can be safely backed out if the insn
  does not match.
  (m68k_compare_opcode): Shortcut the test when the parameters are the same.
  Return 1 if the names match but the second opcode is further on in the array
  than the first.