Fix UB in test_types

Fix (actually, supress) UB in test_types by disabling tests
that cause float-to-long cast

src/tests/test_types.cpp

@@ -182,10 +182,16 @@ TYPED_TEST(TestNumeric, Pow) {
 
     test(0, 100);
     test(22, 12);
-    test(123, 321);
-    test(Type(2.72), Type(1.3123141));
-    test(-102, 11);
-    test(-123, 123);
+    // 123^321 won't fit into long (i. e. IntType) -- it's UB
+    if constexpr (!std::is_same_v<Type, long>) {
+        test(123, 321);
+    }
+    test(Type(2.72), 1.3123141);
+    // -102^11 and -123^123 won't fit into long (i. e. IntType) -- it's UB
+    if constexpr (!std::is_same_v<Type, long>) {
+        test(-102, 11);
+        test(-123, 123);
+    }
     test(-21, -7);
 }