enable warning level for for tests (msvc) and cleanup some warnings.

tests/unordered_map_members_test.h

@@ -16,11 +16,20 @@
 #define PHMAP_CONTAINER_INTERNAL_UNORDERED_MAP_MEMBERS_TEST_H_
 
 #include <type_traits>
+
+#ifdef _MSC_VER
+    #pragma warning(push, 0) 
+#endif
+
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "hash_generator_testing.h"
 #include "hash_policy_testing.h"
 
+#ifdef _MSC_VER
+    #pragma warning(pop) 
+#endif
+
 namespace phmap {
 namespace container_internal {