[wasm] Always provide a wasm instance object at runtime

src/frames.h

 // Copyright 2012 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.
 
 #ifndef V8_FRAMES_H_
 #define V8_FRAMES_H_
 
 #include "src/allocation.h"
 #include "src/handles.h"
 #include "src/safepoint-table.h"
@@ skipping 11 matching lines @@
 int NumRegs(RegList list);
 
 void SetUpJSCallerSavedCodeData();
 
 // Return the code of the n-th saved register available to JavaScript.
 int JSCallerSavedCode(int n);
 
 
 // Forward declarations.
 class ExternalCallbackScope;
+class Isolate;
 class StackFrameIteratorBase;
 class ThreadLocalTop;
-class Isolate;
+class WasmInstanceObject;
 
 class InnerPointerToCodeCache {
  public:
   struct InnerPointerToCodeCacheEntry {
     Address inner_pointer;
     Code* code;
     SafepointEntry safepoint_entry;
   };
 
   explicit InnerPointerToCodeCache(Isolate* isolate) : isolate_(isolate) {
@@ skipping 1057 matching lines @@
              int index) const override;
 
   // Lookup exception handler for current {pc}, returns -1 if none found. Also
   // returns the stack slot count of the entire frame.
   int LookupExceptionHandlerInTable(int* data);
 
   // Determine the code for the frame.
   Code* unchecked_code() const override;
 
   // Accessors.
-  Object* wasm_instance() const;
+  WasmInstanceObject* wasm_instance() const;
   uint32_t function_index() const;
   Script* script() const override;
   int position() const override;
   bool at_to_number_conversion() const;
 
   static WasmFrame* cast(StackFrame* frame) {
     DCHECK(frame->is_wasm());
     return static_cast<WasmFrame*>(frame);
   }
 
@@ skipping 245 matching lines @@
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap(Isolate* isolate, Zone* zone);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_FRAMES_H_