[wasm] prototype for breakpoint support.

src/wasm/wasm-external-refs.h

 // Copyright 2016 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 <stdint.h>
 
 #ifndef WASM_EXTERNAL_REFS_H
 #define WASM_EXTERNAL_REFS_H
 
 namespace v8 {
 namespace internal {
+
+// Forward declaration.
+class JSObject;
+
 namespace wasm {
 
 void f32_trunc_wrapper(float* param);
 
 void f32_floor_wrapper(float* param);
 
 void f32_ceil_wrapper(float* param);
 
 void f32_nearest_int_wrapper(float* param);
 
@@ skipping 29 matching lines @@
 
 int32_t uint64_mod_wrapper(uint64_t* dst, uint64_t* src);
 
 uint32_t word32_ctz_wrapper(uint32_t* input);
 
 uint32_t word64_ctz_wrapper(uint64_t* input);
 
 uint32_t word32_popcnt_wrapper(uint32_t* input);
 
 uint32_t word64_popcnt_wrapper(uint64_t* input);
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 #endif