patch applied (cabal): Add util function allBuildInfo :: PackageDescription -> [BuildInfo]

[Duncan Coutts]

Fri Aug 31 07:39:06 PDT 2007  Duncan Coutts <duncan at haskell.org>
  * Add util function allBuildInfo :: PackageDescription -> [BuildInfo]
  The 'BuildInfo' for the library (if there is one and it's buildable)
  and all the buildable executables. Useful for gathering dependencies.

    M ./Distribution/PackageDescription.hs +11