Use '=default' to define trivial constructor/destructors

https://clang.llvm.org/extra/clang-tidy/checks/modernize/use-equals-default.html

PiperOrigin-RevId: 526079054
Change-Id: Ia4db21e3e5f58b90de05d52fd94b291ed06d785d

googlemock/test/gmock_output_test_.cc

@@ -53,7 +53,7 @@ using testing::Value;
 
 class MockFoo {
  public:
-  MockFoo() {}
+  MockFoo() = default;
 
   MOCK_METHOD3(Bar, char(const std::string& s, int i, double x));
   MOCK_METHOD2(Bar2, bool(int x, int y));