Three lib functions had lost their Hare loud-abort preconditions, so an
out-of-domain argument silently returned garbage instead of aborting:
random.u32n / random.u64n assert(n != 0) ref/hare/math/random/random.ha:26,42
base64.decodedsize assert(sz%4 == 0) ref/hare/encoding/base64/base64.ha:597
Source-bundled lib change, identical on both stages (byte-id neutral).
989_libprecond_abort pins each precondition: n=0 / sz%4!=0 abort (rc!=0),
valid args return 0, run on cstage and wwstage.
Hojun-Cho
46ed712352