[wasm] Add functionality to decode a function offset table

src/wasm/module-decoder.h

Index: src/wasm/module-decoder.h
diff --git a/src/wasm/module-decoder.h b/src/wasm/module-decoder.h
index 00a9b878c6d44a7c4028cfaeea984b171b9d9aeb..dd6bd3bc86ea9609e36e9bbf84b9fc7f31df47da 100644
--- a/src/wasm/module-decoder.h
+++ b/src/wasm/module-decoder.h
@@ -26,6 +26,13 @@ FunctionSig* DecodeWasmSignatureForTesting(Zone* zone, const byte* start,
 FunctionResult DecodeWasmFunction(Isolate* isolate, Zone* zone, ModuleEnv* env,
                                   const byte* function_start,
                                   const byte* function_end);
+
+// Extracts the function offset table from the wasm module bytes.
+// Returns a vector with <offset, length> entries, or failure if the wasm bytes
+// are detected as invalid. Note that this validation is not complete.
+FunctionOffsetsResult DecodeWasmFunctionOffsets(const byte* module_start,
+                                                const byte* module_end);
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8