Merge pull request #547 from ousttrue/fix/is_null

`is null` を `== null` に修正

Assets/MeshUtility/Editor/HumanoidEditor.cs

@@ -200,7 +200,7 @@ namespace MeshUtility
         static string GetDialogDir(UnityEngine.Object obj)
         {
             var prefab = PrefabUtility.GetCorrespondingObjectFromSource(obj);
-            if (prefab is null)
+            if (prefab == null)
             {
                 return null;
             }

Assets/MeshUtility/Runtime/Humanoid.cs

@@ -102,7 +102,7 @@ namespace MeshUtility
         {
             foreach (var prop in props)
             {
-                if (prop.Item2 is null)
+                if (prop.Item2 == null)
                 {
                     var name = prop.Item1;
                     if (name.StartsWith("m_"))
@@ -406,12 +406,12 @@ namespace MeshUtility
         public bool AssignBonesFromAnimator()
         {
             var animator = GetComponent<Animator>();
-            if (animator is null)
+            if (animator == null)
             {
                 return false;
             }
             var avatar = animator.avatar;
-            if (avatar is null)
+            if (avatar == null)
             {
                 return false;
             }

Assets/VRM/UniVRM/Editor/Format/VRMExporterWizard.cs

@@ -131,7 +131,7 @@ namespace VRM
 
         static Vector3 GetForward(Transform l, Transform r)
         {
-            if (l is null || r is null)
+            if (l == null || r == null)
             {
                 return Vector3.zero;
             }
@@ -322,7 +322,7 @@ namespace VRM
         {
             get
             {
-                if (s_func is null)
+                if (s_func == null)
                 {
                     var methods = typeof(EditorGUILayout).GetMethods(BindingFlags.Static | BindingFlags.NonPublic).Where(x => x.Name == "BeginVerticalScrollView").ToArray();
                     var method = methods.First(x => x.GetParameters()[1].ParameterType == typeof(bool));