Bootstrap failure on Linux/x86-64 in Ada

[Bonzini]

Hi Andreas, this should be related to the fixes to AIX toplevel
bootstrap.  My apologies if it is the cause.

Can you try adding these lines to the toplevel Makefile.tpl?

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?

Paolo