Merge pull request #5577 from antrv/fixes/formatted-text-5576

Assign FormattedText._platform in constructor #5576

src/Avalonia.Visuals/Media/FormattedText.cs

@@ -36,7 +36,7 @@ namespace Avalonia.Media
         }
 
         /// <summary>
-        /// 
+        /// Initializes a new instance of the <see cref="FormattedText"/> class.
         /// </summary>
         /// <param name="text"></param>
         /// <param name="typeface"></param>
@@ -45,7 +45,7 @@ namespace Avalonia.Media
         /// <param name="textWrapping"></param>
         /// <param name="constraint"></param>
         public FormattedText(string text, Typeface typeface, double fontSize, TextAlignment textAlignment,
-            TextWrapping textWrapping, Size constraint)
+            TextWrapping textWrapping, Size constraint) : this()
         {
             _text = text;