* src/mcs51/gen.c (getTempRegs): return 0 if not enough registers found,

  (aopPutUsesAcc): added to predict accumulator use,
  (assignResultValue): save acc if necessary,
  (genMinusDec): store result if indirectly addressed,
  (genDivOneByte):  save acc if necessary,
  (movLeft2Result): bugfix if left already in acc,
  (genAnd, genOr, genXor, shiftL2Left2Result, shiftR2Left2Result): pay more
    attention to accumulator use (esp. pdata),
  (genReceive): receive pdata correctly
* src/SDCCicode.c (isOperandInPagedSpace): added to detect pdata operands
* src/SDCCicode.h: added isOperandInPagedSpace prototype

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@3916 4a8a32a2-be11-0410-ad9d-d568d2c75423