Consolidate compilation conditionals around types

By writing a static method `GetTypeInfo` that just returns the passed in
type when `SIMPLE_JSON_TYPEINFO == false` we can use the same code for
both values of the conditional compilation constant
`SIMPLE_JSON_TYPEINFO`.

src/SimpleJson/SimpleJson.cs

@@ -1560,6 +1560,18 @@ class ReflectionUtils
 
             public delegate TValue ThreadSafeDictionaryValueFactory<TKey, TValue>(TKey key);
 
+#if SIMPLE_JSON_TYPEINFO
+            public static TypeInfo GetTypeInfo(Type type)
+            {
+                return type.GetTypeInfo();
+            }
+#else
+            public static Type GetTypeInfo(Type type)
+            {
+                return type;
+            }
+#endif
+
             public static Attribute GetAttribute(MemberInfo info, Type type)
             {
 #if SIMPLE_JSON_TYPEINFO
@@ -1598,11 +1610,7 @@ public static Type[] GetGenericTypeArguments(Type type)
 
             public static bool IsTypeGenericeCollectionInterface(Type type)
             {
-#if SIMPLE_JSON_TYPEINFO
-                if (!type.GetTypeInfo().IsGenericType)
-#else
-                if (!type.IsGenericType)
-#endif
+                if (!GetTypeInfo(type).IsGenericType)
                     return false;
 
                 Type genericDefinition = type.GetGenericTypeDefinition();
@@ -1612,41 +1620,28 @@ public static bool IsTypeGenericeCollectionInterface(Type type)
 
             public static bool IsAssignableFrom(Type type1, Type type2)
             {
-#if SIMPLE_JSON_TYPEINFO
-                return type1.GetTypeInfo().IsAssignableFrom(type2.GetTypeInfo());
-#else
-                return type1.IsAssignableFrom(type2);
-#endif
+                return GetTypeInfo(type1).IsAssignableFrom(GetTypeInfo(type2));
             }
 
             public static bool IsTypeDictionary(Type type)
             {
 #if SIMPLE_JSON_TYPEINFO
                 if (typeof(IDictionary<,>).GetTypeInfo().IsAssignableFrom(type.GetTypeInfo()))
                     return true;
-
-                if (!type.GetTypeInfo().IsGenericType)
-                    return false;
 #else
                 if (typeof(System.Collections.IDictionary).IsAssignableFrom(type))
                     return true;
-
-                if (!type.IsGenericType)
-                    return false;
 #endif
+                if (!GetTypeInfo(type).IsGenericType)
+                    return false;
+
                 Type genericDefinition = type.GetGenericTypeDefinition();
                 return genericDefinition == typeof(IDictionary<,>);
             }
 
             public static bool IsNullableType(Type type)
             {
-                return
-#if SIMPLE_JSON_TYPEINFO
- type.GetTypeInfo().IsGenericType
-#else
- type.IsGenericType
-#endif
- && type.GetGenericTypeDefinition() == typeof(Nullable<>);
+                return GetTypeInfo(type).IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>);
             }
 
             public static object ToNullableType(object obj, Type nullableType)
@@ -1656,11 +1651,7 @@ public static object ToNullableType(object obj, Type nullableType)
 
             public static bool IsValueType(Type type)
             {
-#if SIMPLE_JSON_TYPEINFO
-                return type.GetTypeInfo().IsValueType;
-#else
-                return type.IsValueType;
-#endif
+                return GetTypeInfo(type).IsValueType;
             }
 
             public static IEnumerable<ConstructorInfo> GetConstructors(Type type)