[wasm] Use a Managed<WasmModule> to hold metadata about modules.

src/wasm/module-decoder.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_DECODER_H_
 #define V8_WASM_MODULE_DECODER_H_
 
 #include "src/wasm/ast-decoder.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-result.h"
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
 typedef Result<const WasmModule*> ModuleResult;
 typedef Result<WasmFunction*> FunctionResult;
 typedef std::vector<std::pair<int, int>> FunctionOffsets;
 typedef Result<FunctionOffsets> FunctionOffsetsResult;
 typedef std::vector<std::vector<std::pair<int, int>>> AsmJsOffsets;
 typedef Result<AsmJsOffsets> AsmJsOffsetsResult;
 
 // Decodes the bytes of a WASM module between {module_start} and {module_end}.
-V8_EXPORT_PRIVATE ModuleResult DecodeWasmModule(Isolate* isolate, Zone* zone,
+V8_EXPORT_PRIVATE ModuleResult DecodeWasmModule(Isolate* isolate,
                                                 const byte* module_start,
                                                 const byte* module_end,
                                                 bool verify_functions,
                                                 ModuleOrigin origin);
 
 // Exposed for testing. Decodes a single function signature, allocating it
 // in the given zone. Returns {nullptr} upon failure.
 FunctionSig* DecodeWasmSignatureForTesting(Zone* zone, const byte* start,
                                            const byte* end);
 
@@ skipping 19 matching lines @@
 // is not complete.
 AsmJsOffsetsResult DecodeAsmJsOffsets(const byte* module_start,
                                       const byte* module_end,
                                       uint32_t num_imported_functions);
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_MODULE_DECODER_H_