Use UIUtil.setCursor to prevent setting the cursor that is already set.

Cursor is updated by native code even if component has the same cursor, causing performance problems (IDEA-167733)

platform/platform-impl/src/com/intellij/openapi/editor/impl/EditorGutterComponentImpl.java

@@ -1541,7 +1541,7 @@ class EditorGutterComponentImpl extends EditorGutterComponentEx implements Mouse
         }
       }
     }
-    setCursor(cursor);
+    UIUtil.setCursor(this, cursor);
   }
 
   @Override