locales in buildd environment

[Matthias Klose <doko@cs.tu-berlin.de>]

For correct libstdc++ testresults, the presence for the following
locales is needed:

  de_DE ISO-8859-1
  en_US ISO-8859-1
  fr_FR ISO-8859-1

How can I make sure, that these locales are installed when building
gcc-3.2, gcc-3.3 and gcc-snapshot packages? (Yes, I can check for
these in the rules and abort, but that doesn't help).

Thanks, Matthias