need for flag for incompatible-changes

[Joe Buck]

>  Joe> I agree.  The only reason for some kind of name-munging trick
>  Joe> would be to support old executables that are available only in
>  Joe> binary form.  That's a job that probably isn't worth doing by
>  Joe> the egcs team.  If a specific customer has a need for it, it
>  Joe> might be a nice way for some consultant to make a bit of money.
> 
> That sounds reasonable.  But for it to be possible, the compiler has
> to supply the raw data, i.e., it has to emit the version data into the
> object files.

But these changes I'm describing have nothing to do with the compiler,
really, and everything to do with the library source.  And we already
have a library version number.