Function proc_spawn3 

pub fn proc_spawn3<M: MemorySize>(
    ctx: FunctionEnvMut<'_, WasiEnv>,
    name: WasmPtr<u8, M>,
    name_len: M::Offset,
    args: WasmPtr<WasmPtr<u8, M>, M>,
    args_len: M::Offset,
    envs: WasmPtr<WasmPtr<u8, M>, M>,
    envs_len: M::Offset,
    fd_ops: WasmPtr<ProcSpawnFdOp<M>, M>,
    fd_ops_len: M::Offset,
    signal_actions: WasmPtr<SignalDisposition, M>,
    signal_actions_len: M::Offset,
    search_path: Bool,
    path: WasmPtr<u8, M>,
    path_len: M::Offset,
    ret: WasmPtr<Pid, M>,
) -> Result<Errno, WasiError>

Spawns a new sub-process (posix-spawn style) with proper WasmPtr<WasmPtr<u8>> string lists.

Successor to proc_spawn2. args and envs are pointer arrays of null-terminated strings with args_len / envs_len as element counts. A null envs pointer inherits the current environment.