It's okay for a program to choose to drag in stdio, but it's unfortunate
if even the minimal "int main() { return 42; }" drags in stdio...
This brings the minimal static binary on ARM down from 78KiB to 46KiB.
Given that we don't have a separate -lpthread it's not obvious to me that
we can shave this down any further. I'm not sure whether this is a worthwhile
change for that reason. (And the fact that dynamic binaries, the usual case,
are unaffected either way.)
Change-Id: I02f91dcff37d14354314a30b72fed2563f431c88