tests: Add avm2/edittext_empty_text_format test

This test verifies the text format of empty text.
It is observable in empty input text fields,
because they have to show the caret.

tests/tests/swfs/avm2/edittext_empty_text_format/Test.as

@@ -0,0 +1,30 @@
+package {
+import flash.display.*;
+import flash.text.*;
+import flash.events.*;
+import flash.geom.*;
+
+public class Test extends MovieClip {
+    [Embed(source="TestFont.ttf", fontName="TestFont", embedAsCFF="false", unicodeRange="U+0061-U+0064")]
+    private var TestFont:Class;
+
+    public function Test() {
+        stage.scaleMode = "noScale";
+
+        var field = new TextField();
+        var tf = new TextFormat("TestFont", 10);
+        tf.leading = 5;
+        field.defaultTextFormat = tf;
+        field.type = "input";
+        field.embedFonts = true;
+
+        trace(field.textHeight);
+        trace(field.getLineMetrics(0).ascent);
+        trace(field.getLineMetrics(0).descent);
+        trace(field.getLineMetrics(0).height);
+        trace(field.getLineMetrics(0).leading);
+        trace(field.getLineMetrics(0).width);
+        trace(field.getLineMetrics(0).x);
+    }
+}
+}

tests/tests/swfs/avm2/edittext_empty_text_format/output.txt

@@ -0,0 +1,7 @@
+15
+8
+2
+15
+5
+0
+2

tests/tests/swfs/avm2/edittext_empty_text_format/test.toml

@@ -0,0 +1 @@
+num_ticks = 1