[wasm] Translate locations to positions properly

src/wasm/wasm-objects.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.
 
 #ifndef V8_WASM_OBJECTS_H_
 #define V8_WASM_OBJECTS_H_
 
 #include "src/objects-inl.h"
 #include "src/wasm/managed.h"
 
@@ skipping 253 matching lines @@
   // UTF-8 string.
   static MaybeHandle<String> GetFunctionName(
       Handle<WasmCompiledModule> compiled_module, uint32_t func_index);
 
   // Get the raw bytes of the function name of the function identified by the
   // given index.
   // Meant to be used for debugging or frame printing.
   // Does not allocate, hence gc-safe.
   Vector<const uint8_t> GetRawFunctionName(uint32_t func_index);
 
+  // Return the byte offset of the function identified by the given index.
+  // The offset will be relative to the start of the module bytes.
+  // Returns -1 if the function index is invalid.
+  int GetFunctionOffset(uint32_t func_index) const;
+
  private:
   void InitId();
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WasmCompiledModule);
 };
 
 class WasmDebugInfo : public FixedArray {
  public:
   enum class Fields { kFieldCount };
 
@@ skipping 27 matching lines @@
                                     int func_index, int byte_offset);
 };
 
 #undef DECLARE_ACCESSORS
 #undef DECLARE_OPTIONAL_ACCESSORS
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_OBJECTS_H_