Fix redundant redeclaration warning

Fixes #4200

PiperOrigin-RevId: 520017094
Change-Id: Id707a1c0489edde083771ccd412d7035612474dc
diff --git a/googlemock/include/gmock/internal/gmock-internal-utils.h b/googlemock/include/gmock/internal/gmock-internal-utils.h
index b5283ed..d344438 100644
--- a/googlemock/include/gmock/internal/gmock-internal-utils.h
+++ b/googlemock/include/gmock/internal/gmock-internal-utils.h
@@ -465,8 +465,10 @@
   using MakeResultIgnoredValue = IgnoredValue(Args...);
 };
 
+#ifdef GTEST_INTERNAL_NEED_REDUNDANT_CONSTEXPR_DECL
 template <typename R, typename... Args>
 constexpr size_t Function<R(Args...)>::ArgumentCount;
+#endif
 
 // Workaround for MSVC error C2039: 'type': is not a member of 'std'
 // when std::tuple_element is used.