[cvs-nhc98] patch applied (cpphs): Expand macros during first (conditional) phase of processing.

[Malcolm Wallace]

Mon Jun  4 13:44:22 PDT 2007  Malcolm.Wallace at cs.york.ac.uk
  * Expand macros during first (conditional) phase of processing.
  When dealing with #if and #include in the first pass over the file,
  use proper macro expansion (only on the cpp # directive lines).
  Believed to be working, but may not yet quite match cpp behaviour.

    M ./Language/Preprocessor/Cpphs/CppIfdef.hs -25 +44
    M ./Language/Preprocessor/Cpphs/MacroPass.hs -10 +14
    M ./Language/Preprocessor/Cpphs/ReadFirst.hs -9 +12