Have WasmModule free it's own memory.

test/unittests/wasm/ast-decoder-unittest.cc

 // 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.
 
 #include "test/unittests/test-utils.h"
 
 #include "src/v8.h"
 
 #include "test/cctest/wasm/test-signatures.h"
 
@@ skipping 1171 matching lines @@
 // A helper for tests that require a module environment for functions and
 // globals.
 class TestModuleEnv : public ModuleEnv {
  public:
   TestModuleEnv() {
     mem_start = 0;
     mem_end = 0;
     module = &mod;
     linker = nullptr;
     function_code = nullptr;
-    mod.globals = &globals;
-    mod.signatures = &signatures;
-    mod.functions = &functions;
+    mod.globals = new std::vector<WasmGlobal>;
+    mod.signatures = new std::vector<FunctionSig*>;
+    mod.functions = new std::vector<WasmFunction>;
   }
   byte AddGlobal(MachineType mem_type) {
-    globals.push_back({0, mem_type, 0, false});
-    CHECK(globals.size() <= 127);
-    return static_cast<byte>(globals.size() - 1);
+    mod.globals->push_back({0, mem_type, 0, false});
+    CHECK(mod.globals->size() <= 127);
+    return static_cast<byte>(mod.globals->size() - 1);
   }
   byte AddSignature(FunctionSig* sig) {
-    signatures.push_back(sig);
-    CHECK(signatures.size() <= 127);
-    return static_cast<byte>(signatures.size() - 1);
+    mod.signatures->push_back(sig);
+    CHECK(mod.signatures->size() <= 127);
+    return static_cast<byte>(mod.signatures->size() - 1);
   }
   byte AddFunction(FunctionSig* sig) {
-    functions.push_back({sig, 0, 0, 0, 0, 0, 0, 0, false, false});
-    CHECK(functions.size() <= 127);
-    return static_cast<byte>(functions.size() - 1);
+    mod.functions->push_back({sig, 0, 0, 0, 0, 0, 0, 0, false, false});
+    CHECK(mod.functions->size() <= 127);
+    return static_cast<byte>(mod.functions->size() - 1);
   }
 
  private:
   WasmModule mod;
-  std::vector<WasmGlobal> globals;
-  std::vector<FunctionSig*> signatures;
-  std::vector<WasmFunction> functions;
 };
 }  // namespace
 
 
 TEST_F(WasmDecoderTest, SimpleCalls) {
   FunctionEnv* env = &env_i_i;
   TestModuleEnv module_env;
   env->module = &module_env;
 
   module_env.AddFunction(sigs.i_v());
@@ skipping 1151 matching lines @@
   EXPECT_ARITY(1, kExprF64SConvertI64);
   EXPECT_ARITY(1, kExprF64UConvertI64);
   EXPECT_ARITY(1, kExprF64ConvertF32);
   EXPECT_ARITY(1, kExprF64ReinterpretI64);
   EXPECT_ARITY(1, kExprI32ReinterpretF32);
   EXPECT_ARITY(1, kExprI64ReinterpretF64);
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8