Add memory64 support to the Wasmtime CLI and C API (#3182)

Accidentally forgotten from #3153!

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

@@ -192,6 +192,14 @@ WASMTIME_CONFIG_PROP(void, wasm_multi_memory, bool)
  */
 WASMTIME_CONFIG_PROP(void, wasm_module_linking, bool)
 
+/**
+ * \brief Configures whether the WebAssembly memory64 proposal is
+ * enabled.
+ *
+ * This setting is `false` by default.
+ */
+WASMTIME_CONFIG_PROP(void, wasm_memory64, bool)
+
 /**
  * \brief Configures how JIT code will be compiled.
  *

crates/c-api/src/config.rs

@@ -100,6 +100,11 @@ pub extern "C" fn wasmtime_config_wasm_module_linking_set(c: &mut wasm_config_t,
     c.config.wasm_module_linking(enable);
 }
 
+#[no_mangle]
+pub extern "C" fn wasmtime_config_wasm_memory64_set(c: &mut wasm_config_t, enable: bool) {
+    c.config.wasm_memory64(enable);
+}
+
 #[no_mangle]
 pub extern "C" fn wasmtime_config_strategy_set(
     c: &mut wasm_config_t,