[wasm] remove unused WasmInstance fields

src/wasm/wasm-module.h

Index: src/wasm/wasm-module.h
diff --git a/src/wasm/wasm-module.h b/src/wasm/wasm-module.h
index bf4c29999c3ccf38fee54d519173a02ff01b0d10..d4d4ec64559dbb791c9c268cd5c0336eadf7b69f 100644
--- a/src/wasm/wasm-module.h
+++ b/src/wasm/wasm-module.h
@@ -232,10 +232,7 @@ typedef Managed<WasmModule> WasmModuleWrapper;
 struct WasmInstance {
   const WasmModule* module;  // static representation of the module.
   // -- Heap allocated --------------------------------------------------------
-  Handle<JSObject> js_object;            // JavaScript module object.
   Handle<Context> context;               // JavaScript native context.
-  Handle<JSArrayBuffer> mem_buffer;      // Handle to array buffer of memory.
-  Handle<JSArrayBuffer> globals_buffer;  // Handle to array buffer of globals.
   std::vector<Handle<FixedArray>> function_tables;  // indirect function tables.
   std::vector<Handle<Code>> function_code;  // code objects for each function.
   // -- raw memory ------------------------------------------------------------