[wasm] Add functionality to decode a function offset table

src/wasm/wasm-module.h

 // 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.
 
 #ifndef V8_WASM_MODULE_H_
 #define V8_WASM_MODULE_H_
 
 #include "src/api.h"
 #include "src/handles.h"
 #include "src/wasm/wasm-opcodes.h"
@@ skipping 289 matching lines @@
   WasmFunctionName(const WasmFunction* function, const ModuleEnv* menv)
       : function_(function), module_(menv ? menv->module : nullptr) {}
 };
 
 std::ostream& operator<<(std::ostream& os, const WasmModule& module);
 std::ostream& operator<<(std::ostream& os, const WasmFunction& function);
 std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name);
 
 typedef Result<const WasmModule*> ModuleResult;
 typedef Result<WasmFunction*> FunctionResult;
+typedef std::vector<std::pair<int, int>> FunctionOffsets;
+typedef Result<FunctionOffsets> FunctionOffsetsResult;
 
 // For testing. Decode, verify, and run the last exported function in the
 // given encoded module.
 int32_t CompileAndRunWasmModule(Isolate* isolate, const byte* module_start,
                                 const byte* module_end, bool asm_js = false);
 
 // For testing. Decode, verify, and run the last exported function in the
 // given decoded module.
 int32_t CompileAndRunWasmModule(Isolate* isolate, const WasmModule* module);
 
@@ skipping 14 matching lines @@
 // secure. If it turns out that we need more complete checks, we could add a
 // special marker as internal field, which will definitely never occur anywhere
 // else.
 bool IsWasmObject(Handle<JSObject> object);
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_MODULE_H_