* arith.c (plus, minus, mul, gt, ge, lt, le, exptmod, gcd): Remove trailing abort; we already marked uw_throwf as noreturn. This hack should not be needed in functions where the last statement is a throw. (trunc, expt): Repeated error case handled in one place. Temp variable used to avoid two calls to mp_clear. Call to abort removed. (mod): Repeated error handed in one place. Plugged memory leak by moving throw past mp_clear calls. Call to abort removed. (isqrt): Repeated error case handed in one place.