[committed] MIPS/include: opcode/mips.h: Add a summary of MIPS16 operand codes

[Maciej W. Rozycki]

    	include/
    	* opcode/mips.h: Add a summary of MIPS16 operand codes.
---
 I've noticed a summary of operand codes is missing for the MIPS16 ISA, so 
I have committed this change, for consistency with the regular MIPS and 
the microMIPS ISA.

  Maciej

diff --git a/include/opcode/mips.h b/include/opcode/mips.h
index dcc8680..88bf8f8 100644
--- a/include/opcode/mips.h
+++ b/include/opcode/mips.h
@@ -1825,6 +1825,12 @@ extern int bfd_mips_num_opcodes;
    "E" 5 bit PC relative address * 4 (MIPS16OP_*_IMM5)
    "m" 7 bit register list for save instruction (18 bit extended)
    "M" 7 bit register list for restore instruction (18 bit extended)
+
+   Characters used so far, for quick reference when adding more:
+   "   456 8 0"
+   "[]<>"
+   "ABCDE  HI KLM  P RS UVWXYZ"
+   "a   e   ijklm  pq    vwxyz"
   */
 
 /* Save/restore encoding for the args field when all 4 registers are