test: make sure vtable is generated in addon test with LTO

PR-URL: #28057
Fixes: #28026
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

Author: addaleax

test/addons/uv-handle-leak/binding.cc

@@ -15,9 +15,16 @@ void CloseCallback(uv_handle_t* handle) {}
 
 class ExampleOwnerClass {
  public:
-  virtual ~ExampleOwnerClass() {}
+  virtual ~ExampleOwnerClass();
 };
 
+// Do not inline this into the class, because that may remove the virtual
+// table when LTO is used, and with it the symbol for which we grep the process
+// output in test/abort/test-addon-uv-handle-leak.
+// When the destructor is not inlined, the compiler will have to assume that it,
+// and the vtable, is part of what this compilation unit exports, and keep them.
+ExampleOwnerClass::~ExampleOwnerClass() {}
+
 ExampleOwnerClass example_instance;
 
 void LeakHandle(const FunctionCallbackInfo<Value>& args) {