pub fn fd_pwrite<M: Memory>(
    ctx: &mut WasiCtx,
    mem: &mut M,
    fd: __wasi_fd_t,
    iovs: WasmPtr<__wasi_ciovec_t>,
    iovs_len: __wasi_size_t,
    offset: __wasi_filesize_t,
    nwritten: WasmPtr<__wasi_size_t>
) -> Result<(), Errno>