Bootstrap failure on Linux/x86-64 in Ada

[Arnaud Charlet]

> ADAFLAGS = -W -Wall -gnatpg -gnata
> ADAFLAGS_FOR_TARGET = -W -Wall -gnatpg -gnata
> 
> and changing = to += in config/mt-ppc-aix?
> 
> Arnaud, it seems strange that "required" flags like -gnatpg are on
> ADAFLAGS rather than the makefile rules.  -c is not in CFLAGS, for
> example.  Is it possible that you don't want -gnatpg in some cases?

Yes, -gnatp is certainly not required in all cases (e.g. for debugging).

Of course that does not change the fact that we want a reasonable
default value for ADAFLAGS, that is *not* overriden by default by the top-level
Makefiles, only by users and build scripts. And I'd rather keep this default
in ada/Makefile.in rather than moving it to the top level.

Arno