[wasm] Use more precise types for some WASM objects.

test/cctest/wasm/test-run-wasm-module.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 #include <string.h>
 
 #include "src/snapshot/code-serializer.h"
 #include "src/version.h"
 #include "src/wasm/module-decoder.h"
@@ skipping 518 matching lines @@
                                     WASM_I32V(InterruptThread::signal_value_)),
                      WASM_BR(1))),
         WASM_I32V(121)};
     f->EmitCode(code, sizeof(code));
     ZoneBuffer buffer(&zone);
     builder->WriteTo(buffer);
 
     HandleScope scope(isolate);
     testing::SetupIsolateForWasmModule(isolate);
     ErrorThrower thrower(isolate, "Test");
-    const Handle<JSObject> instance =
+    const Handle<WasmInstanceObject> instance =
         testing::CompileInstantiateWasmModuleForTesting(
             isolate, &thrower, buffer.begin(), buffer.end(),
             ModuleOrigin::kWasmOrigin);
     CHECK(!instance.is_null());
 
     MaybeHandle<JSArrayBuffer> maybe_memory =
         GetInstanceMemory(isolate, instance);
     Handle<JSArrayBuffer> memory = maybe_memory.ToHandleChecked();
     int32_t* memory_array = reinterpret_cast<int32_t*>(memory->backing_store());
 
@@ skipping 357 matching lines @@
     };
 
     testing::CompileInstantiateWasmModuleForTesting(isolate, &thrower, data,
                                                     data + arraysize(data),
                                                     ModuleOrigin::kWasmOrigin);
     // It should be possible to instantiate this module.
     CHECK(!thrower.error());
   }
   Cleanup();
 }