patch for -Wno-long-long and early GNAT compilers

[Richard Kenner]

    I can understand ACT's position of recommending its own builds for
    bootstrapping, and I can see how it may be justifiable with the
    scarcity of human resources available to GNAT working with multiple
    bootstrap compilers.

Note that this is a very transient issue and only an issue because there
was no previous FSF version of GNAT.  Once there is, it will be possible
to precisely define what compiler is to be used in terms of previous
versions of GCC.  The problem comes up now because there are so many
possible ways of building GNAT and some of them obviously have bugs.

After the 3.1 GCC release (in which GNAT will work, though not be "supported"),
we can just say that version is required to build the version for 3.2
and that will be the end of this problem.

So basically we have a problem that will go away in about a month and
I don't see why we need to spend so much time debating it.