avm2: Do not enumerate fonts without a layout

Flash does not enumerate fonts which do not have a layout defined.
Fonts without a layout are used only to refer to existing fonts
and they do not provide glyphs.

core/src/avm2/globals/flash/text/font.rs

@@ -115,7 +115,7 @@ pub fn enumerate_fonts<'gc>(
         for font in library.embedded_fonts() {
             // TODO: EmbeddedCFF isn't supposed to show until it's been used (some kind of internal initialization method?)
             // Device is only supposed to show when arg0 is true - but that's supposed to be "all known" device fonts, not just loaded ones
-            if font.font_type() == FontType::Embedded {
+            if font.has_layout() && font.font_type() == FontType::Embedded {
                 storage.push(FontObject::for_font(activation.gc(), font_class, font).into());
             }
         }

core/src/font.rs

@@ -363,6 +363,12 @@ struct FontData {
     descriptor: FontDescriptor,
 
     font_type: FontType,
+
+    /// Whether this font has a layout defined.
+    ///
+    /// Fonts without a layout are used only to describe a font,
+    /// not to provide glyphs.
+    has_layout: bool,
 }
 
 impl<'gc> Font<'gc> {
@@ -385,6 +391,7 @@ impl<'gc> Font<'gc> {
                 glyphs: GlyphSource::FontFace(face),
                 descriptor,
                 font_type,
+                has_layout: true,
             },
         )))
     }
@@ -463,6 +470,7 @@ impl<'gc> Font<'gc> {
                 leading,
                 descriptor,
                 font_type,
+                has_layout: tag.layout.is_some(),
             },
         ))
     }
@@ -513,6 +521,7 @@ impl<'gc> Font<'gc> {
                 glyphs: GlyphSource::Empty,
                 descriptor,
                 font_type,
+                has_layout: true,
             },
         ))
     }
@@ -759,6 +768,10 @@ impl<'gc> Font<'gc> {
     pub fn font_type(&self) -> FontType {
         self.0.font_type
     }
+
+    pub fn has_layout(&self) -> bool {
+        self.0.has_layout
+    }
 }
 
 #[derive(Debug, Clone)]