decompile: avoid single-subexpression `begin0`
decompile: avoid single-subexpression `begin0`

At the bytecode level, `(begin0 E)` does not make E in tail position
with respect to the `begin0` form. It does at the source level, so
generate suitable source.

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket