message: chore(api) `use std::ffi::c_void` to simplify code.
diff: @@ -11,6 +11,7 @@ pub use inner::{FromToNativeWasmType, HostFunction, WasmTypeList, WithEnv, Witho
  pub use inner::{UnsafeMutableEnv, WithUnsafeMutableEnv};
  use std::cmp::max;
  +use std::ffi::c_void;
  use std::fmt;
  use std::sync::Arc;
  use wasmer_engine::{Export, ExportFunction, ExportFunctionMetadata};
  @@ -73,14 +74,14 @@ fn build_export_function_metadata<Env>(
  &'a mut Env,
  &'a crate::Instance,
  ) -> Result<(), crate::HostEnvInitError>,
  -) -> (*mut std::ffi::c_void, ExportFunctionMetadata)
  +) -> (*mut c_void, ExportFunctionMetadata)
  where
  Env: Clone + Sized + 'static + Send + Sync,
  {
  let import_init_function_ptr = Some(unsafe {
  std::mem::transmute::<_, ImportInitializerFuncPtr>(import_init_function_ptr)
  });
  - let host_env_clone_fn: fn(*mut std::ffi::c_void) -> *mut std::ffi::c_void = |ptr| {
  + let host_env_clone_fn = |ptr: *mut c_void| -> *mut c_void {
  let env_ref: &Env = unsafe {
  ptr.cast::<Env>()
  .as_ref()
  @@ -88,7 +89,7 @@ where
  };
  Box::into_raw(Box::new(env_ref.clone())) as _
  };
  - let host_env_drop_fn: fn(*mut std::ffi::c_void) = |ptr| {
  + let host_env_drop_fn = |ptr: *mut c_void| {
  unsafe { Box::from_raw(ptr.cast::<Env>()) };
  };
  let env = Box::into_raw(Box::new(env)) as _;
  @@ -159,7 +160,7 @@ impl Function {
  let address = std::ptr::null() as *const VMFunctionBody;
  let host_env = Box::into_raw(Box::new(dynamic_ctx)) as *mut _;
  let vmctx = VMFunctionEnvironment { host_env };
  - let host_env_clone_fn: fn(*mut std::ffi::c_void) -> *mut std::ffi::c_void = |ptr| {
  + let host_env_clone_fn: fn(*mut c_void) -> *mut c_void = |ptr| {
  let duped_env: VMDynamicFunctionContext<DynamicFunctionWithoutEnv> = unsafe {
  let ptr: *mut VMDynamicFunctionContext<DynamicFunctionWithoutEnv> = ptr as _;
  let item: &VMDynamicFunctionContext<DynamicFunctionWithoutEnv> = &*ptr;
  @@ -167,7 +168,7 @@ impl Function {
  };
  Box::into_raw(Box::new(duped_env)) as _
  };
  - let host_env_drop_fn: fn(*mut std::ffi::c_void) = |ptr: *mut std::ffi::c_void| {
  + let host_env_drop_fn: fn(*mut c_void) = |ptr: *mut c_void| {
  unsafe {
  Box::from_raw(ptr as *mut VMDynamicFunctionContext<DynamicFunctionWithoutEnv>)
  };
  