moved matrix4.flattenToArrayOffset to legacy

src/Three.Legacy.js

@@ -277,6 +277,11 @@ Object.assign( Matrix4.prototype, {
 		console.warn( 'THREE.Matrix4: .extractPosition() has been renamed to .copyPosition().' );
 		return this.copyPosition( m );
 	},
+	flattenToArrayOffset: function ( array, offset ) {
+		console.warn( "THREE.Matrix4: .flattenToArrayOffset() has been deprecated. Use .toArray() instead." );
+
+		return this.toArray( array, offset );
+	},
 	setRotationFromQuaternion: function ( q ) {
 		console.warn( 'THREE.Matrix4: .setRotationFromQuaternion() has been renamed to .makeRotationFromQuaternion().' );
 		return this.makeRotationFromQuaternion( q );

src/math/Matrix4.js

@@ -567,15 +567,6 @@ Matrix4.prototype = {
 
 	},
 
-	flattenToArrayOffset: function ( array, offset ) {
-
-		console.warn( "THREE.Matrix3: .flattenToArrayOffset is deprecated " +
-				"- just use .toArray instead." );
-
-		return this.toArray( array, offset );
-
-	},
-
 	getPosition: function () {
 
 		var v1;