Ada policy

[Florian Weimer]

* Robert Dewar:

> That's just not true. GNAT has been able to be built from 3.13 for
> many years (3.13 was released several years ago). We only introduce
> incompatibilities if we really need to for some significant cleanup
> or kludge removal. Earlier on that was more common, but we have not
> needed to do that for many years now.

I wonder why it's not possible to disable some aspects of -gnatg when
building the stage1 compiler.  If there was such an option, you might
be able to do some cleanups (like instrumenting the code with more
precise pragmas to control warnings) without requiring newer compiler
versions to bootstrap.