Avoid uses of ?. in locations that are not Babeled (#25880)

Avoid uses of ?. in locations that are not Babeled, to help Firefox
68.12.0esr pass browser tests.

Author: juj

src/modularize.js

@@ -18,7 +18,12 @@ var {{{ EXPORT_NAME }}} = (() => {
   // When MODULARIZE this JS may be executed later,
   // after document.currentScript is gone, so we save it.
   // In EXPORT_ES6 mode we can just use 'import.meta.url'.
+#if MIN_FIREFOX_VERSION < 74 || LEGACY_VM_SUPPORT
+  // This modularize.js script is not Babeled, so manually adapt for old browsers.
+  var _scriptName = typeof document !== 'undefined' && document.currentScript ? document.currentScript.src : undefined;
+#else
   var _scriptName = globalThis.document?.currentScript?.src;
+#endif
   return async function(moduleArg = {}) {
     var moduleRtn;
 

test/browser_reporting.js

@@ -125,12 +125,12 @@ if (hasModule) {
     const origPrintErr = Module['printErr'];
 
     Module['print'] = (...args) => {
-      origPrint?.(...args);
+      origPrint && origPrint(args);
       reportStdoutToServer(args.join(' '));
     };
 
     Module['printErr'] = (...args) => {
-      origPrintErr?.(...args);
+      origPrintErr && origPrintErr(args);
       reportStderrToServer(args.join(' '));
     };
   }

tools/file_packager.py

@@ -1017,7 +1017,7 @@ def generate_preload_js(data_target, data_files, metadata):
       # is async, so we handle both orderings.
       ret += '''
       var fetchPromise;
-      var fetched = Module['getPreloadedPackage']?.(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE);
+      var fetched = Module['getPreloadedPackage'] && Module['getPreloadedPackage'](REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE);
 
       if (!fetched) {
         // Note that we don't use await here because we want to execute the