Tidy up some headers related to shared memory (#8366)

* Tidy up some headers related to shared memory

* Don't declare an anonymous `struct wasmtime_sharedmemory`, instead
  `#include` the actual definition.
* Fix an issue where a header in `sharedmemory.h` referred to a type in
  `extern.h` which wasn't `#include`'d. This function,
  `wasmtime_sharedmemory_into_extern`, additionally isn't necessary as
  it's no different than manually constructing it. Fix this by removing
  this function.

* Run clang-format

crates/c-api/include/wasmtime/extern.h

@@ -8,6 +8,7 @@
 #define WASMTIME_EXTERN_H
 
 #include <wasmtime/module.h>
+#include <wasmtime/sharedmemory.h>
 #include <wasmtime/store.h>
 
 #ifdef __cplusplus
@@ -89,8 +90,6 @@ typedef uint8_t wasmtime_extern_kind_t;
 /// shared memory
 #define WASMTIME_EXTERN_SHAREDMEMORY 4
 
-struct wasmtime_sharedmemory;
-
 /**
  * \typedef wasmtime_extern_union_t
  * \brief Convenience alias for #wasmtime_extern_union

crates/c-api/include/wasmtime/sharedmemory.h

@@ -56,18 +56,6 @@ wasmtime_sharedmemory_delete(wasmtime_sharedmemory_t *memory);
 WASM_API_EXTERN wasmtime_sharedmemory_t *
 wasmtime_sharedmemory_clone(const wasmtime_sharedmemory_t *memory);
 
-/**
- * \brief Moves shared linear memory into wasmtime_extern_t object
- *
- * \param memory memory to be moved
- * \param out where to store resulting `wasmtime_extern_t`
- *
- * This function moves ownership of `memory` into resulting `wasmtime_extern_t`.
- */
-WASM_API_EXTERN void
-wasmtime_sharedmemory_into_extern(wasmtime_sharedmemory_t *memory,
-                                  wasmtime_extern_t *out);
-
 /**
  * \brief Returns the type of the shared memory specified
  */

crates/c-api/src/sharedmemory.rs

@@ -1,7 +1,6 @@
-use crate::{handle_result, wasm_memorytype_t, wasmtime_error_t, wasmtime_extern_t};
+use crate::{handle_result, wasm_memorytype_t, wasmtime_error_t};
 use std::cell::UnsafeCell;
-use std::mem::MaybeUninit;
-use wasmtime::{Extern, SharedMemory};
+use wasmtime::SharedMemory;
 
 type wasmtime_sharedmemory_t = SharedMemory;
 
@@ -27,14 +26,6 @@ pub extern "C" fn wasmtime_sharedmemory_clone(
     Box::new(mem.clone())
 }
 
-#[no_mangle]
-pub extern "C" fn wasmtime_sharedmemory_into_extern(
-    mem: Box<wasmtime_sharedmemory_t>,
-    ext: &mut MaybeUninit<wasmtime_extern_t>,
-) {
-    crate::initialize(ext, Extern::from(*mem).into());
-}
-
 #[no_mangle]
 pub extern "C" fn wasmtime_sharedmemory_type(
     mem: &wasmtime_sharedmemory_t,