Fix (once and for all, hopefully) the shfmt/gosh bridge (JSON deserialization)

See https://github.com/katexochen/sh/commit/4175a00e1a5c61d0c5fe7f6cb98b081be97af82a
Currently the translation layer doesn't work due to the issue described in the commit. However, fixing it now should guarantee it's gonna work for all future versions of shfmt.