* src/pic16/{pcode.h,genarith.c}:

* src/pic16/{pcode.h,genarith.c}:
  introduced pCodeOp combining any two pCodeOps (previously only
  two register operands could be combined), removed pcop2 from
  pCodepReg, replaced pCodeOpReg2 with pCodeOp2, fixes #1492366
* src/pic16/pcodepeep.c (pic16_pCodeOpCopy): added case for PO_TWO_OPS
* src/pic16/gen.c (pic16_popGet2,pic16_popGet2p,pic16_popCombine2):
  rewritten to use new PO_TWO_OPS
* src/pic16/main.c (_hasNativeMulFor): cover more cases natively,
* src/pic16/pcode.c (pic16_newpCodeOpImmd): initialize rIdx field,
  (pic16_newpCodeOp): catch invalid attempts on PO_TWO_OPS,
  (pic16_newpCodeOp2): NEW, create combined pCodeOp,
  (pic16_get_op): embraced return arg to allow #define return(x),
    added new case for combined opcodes
  (pic16_get_op2): reduced to use pic16_get_op() on second pCodeOp,
  (pic16_pCode2str,pic16_getRegFrompCodeOp,
   pic16_getRegFromInstruction2): fixed/added handling of new pCodeOp

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@4209 4a8a32a2-be11-0410-ad9d-d568d2c75423