Re: Move GCCBUGURL to version.c; add commentary

[kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)]

    > The problem with the normal ICE message is that it does not provide
    > helpful information about where exactly the error is coming from.
    > GNAT provides the exact location (including column) ...

    This is only useful if the parser itself crashes.  Which
    is practically never the case, at least in my experience.

That's not the case in Ada.  Most failures are either in the Ada part
of the front end or the interface between it and the core of GCC.

    Once you get into the optimizers, the only location you can glean is
    the function.

Even then, the line number is still useful because it can often be hard to
locate the function if it's nested or in a generic.