The idea currently is to make these values
explicit so that when people read system.ads, they know right away what
the right value is.
That's "when people read system.ads", not "when people read
system-linux-x86.ads". In other words, he's not necessarily against
automatically generating system.ads from other means, for example using
configure tests. Which, I repeat, comes out naturally if the RTS build is
confined in libada.
Right, that's one possibility, although people seem to be focusing
in system.ads alot, which is actually only the tip of the iceberg, and not
a real issue per se.