[cvs-nhc98] patch applied (hat): Add a new faster implementation of input I/O.

[Malcolm Wallace]

Tue Feb 13 06:12:18 PST 2001  malcolm
  * Add a new faster implementation of input I/O.
  
    * There is a new bytecode instruction HGETS, and a new primitive
          Builtin.hgets that uses it.
    * The compiler recognises a special symbol _hGetStr and generates
          the new bytecode HGETS for it.
    * IO.hGetContents uses the special symbol _hGetStr, and hence the
          new bytecode.
  
  We achieve a 1.5x to 3x speed-up for raw lazy input.  Unless a real
  program is very heavily input-bound, this won't give a vast saving,
  but for instance nhc98 is now 2.5% faster at building itself.
  
  Note: because the bytecodes have changed, this commit is a BREAKING
  change.  You cannot mix old compiled code with new compiled code.

    M ./src/compiler98/GcodeLow.hs -1 +2
    M ./src/compiler98/Prim.hs +2
    M ./src/compiler98/PrimCode.hs +3