test: make CreateParams stack-allocated

PR-URL: #17366
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

test/cctest/node_test_fixture.h

@@ -61,7 +61,6 @@ class NodeTestFixture : public ::testing::Test {
   node::MultiIsolatePlatform* Platform() const { return platform_; }
 
  protected:
-  v8::Isolate::CreateParams params_;
   v8::Isolate* isolate_;
 
   ~NodeTestFixture() {
@@ -73,6 +72,7 @@ class NodeTestFixture : public ::testing::Test {
     platform_ = new node::NodePlatform(8, nullptr);
     v8::V8::InitializePlatform(platform_);
     v8::V8::Initialize();
+    v8::Isolate::CreateParams params_;
     params_.array_buffer_allocator = allocator_.get();
     isolate_ = v8::Isolate::New(params_);
   }