[WebXR] Fix closure compiler mangling `XRSession.enabledFeatures`

modules/webxr/native/library_godot_webxr.js

@@ -320,7 +320,8 @@ const GodotWebXR = {
 					// next reference space.
 					window.setTimeout(function () {
 						const reference_space_c_str = GodotRuntime.allocString(reference_space_type);
-						const enabled_features_c_str = GodotRuntime.allocString(Array.from(session.enabledFeatures).join(','));
+						const enabled_features = 'enabledFeatures' in session ? Array.from(session.enabledFeatures) : [];
+						const enabled_features_c_str = GodotRuntime.allocString(enabled_features.join(','));
 						onstarted(reference_space_c_str, enabled_features_c_str);
 						GodotRuntime.free(reference_space_c_str);
 						GodotRuntime.free(enabled_features_c_str);

modules/webxr/native/webxr.externs.js

@@ -77,6 +77,11 @@ XRSession.prototype.frameRate;
  */
 XRSession.prototype.supportedFrameRates;
 
+/**
+ * @type {Array<string>}
+ */
+XRSession.prototype.enabledFeatures;
+
 /**
  * @type {?function (Event)}
  */