[cvs-nhc98] patch applied (hat): Fix lexical error (masquerading as a parse error) with an underscore

[Malcolm Wallace]

Tue Jun 14 03:25:53 PDT 2005  malcolm
  * Fix lexical error (masquerading as a parse error) with an underscore
  pattern e.g. "f _2a", when the -underscore flag is off (the default).
  Because the character following the underscore is neither lower nor
  upper, nhc98's special treatment (ignore the underscore in deciding
  whether it is a conid or varid) does not apply.  Thus, drop through to
  the standard H'98 behaviour of underscore=lowercase, therefore a varid.

    M ./src/compiler98/LexLow.hs -1 +2