patch applied (ghc-6.6/ghc): Make it a warning, not an error, if the version date cannot be determined

[Simon Marlow]

Thu Feb  8 07:13:23 PST 2007  Simon Marlow <simonmar at microsoft.com>
  * Make it a warning, not an error, if the version date cannot be determined
  This happens when the build tree is a link-tree to the source tree,
  because lndir will normally omit the _darcs directory.

    M ./aclocal.m4 -1 +1