avm2: Convert flash.geom.Matrix to ActionScript

I've kept the rust `flash.geom` module, even though it's now empty,
since we'll need to add things like `flash.geom.Transform` native
methods in the future.

core/src/avm2/globals.rs

@@ -819,7 +819,6 @@ pub fn load_player_globals<'gc>(
     )?;
 
     // package `flash.geom`
-    class(activation, flash::geom::matrix::create_class(mc), script)?;
 
     // package `flash.media`
     avm2_system_class!(

core/src/avm2/globals/flash/geom.rs

@@ -1,3 +1 @@
 //! `flash.geom` namespace
-
-pub mod matrix;

core/src/avm2/globals/flash/geom/Matrix.as

@@ -0,0 +1,33 @@
+package flash.geom {
+	public class Matrix {
+		public var a:Number;
+		public var b:Number;
+		public var c:Number;
+		public var d:Number;
+		public var tx:Number;
+		public var ty:Number;
+
+		public function Matrix(a:Number = 1, b:Number = 0, c:Number = 0, d:Number = 1, tx:Number = 0, ty:Number = 0) {
+			this.a = a;
+			this.b = b;
+			this.c = c;
+			this.d = d;
+			this.tx = tx;
+			this.ty = ty;
+		}
+
+		public function identity():void {
+			this.a = 1;
+			this.b = 0;
+			this.c = 0;
+			this.d = 1;
+			this.tx = 0;
+			this.ty = 0;
+		}
+
+		public function scale(sx:Number, sy:Number):void {
+			this.a *= sx;
+			this.d *= sy;
+		}
+	}
+}

core/src/avm2/globals/globals.as

@@ -30,6 +30,7 @@ include "flash/display/SWFVersion.as"
 include "flash/display/TriangleCulling.as"
 include "flash/geom/ColorTransform.as"
 include "flash/geom/Orientation3D.as"
+include "flash/geom/Matrix.as"
 include "flash/geom/Point.as"
 include "flash/geom/Rectangle.as"
 include "flash/net/SharedObjectFlushStatus.as"