Avoiding exporting ready promise. NFC

This promise is defined and used only in MODULARIZE mode and the
promise itself is returned, so there is no need to export it on the
Module object.

src/parseTools.js

@@ -935,7 +935,7 @@ function to64(x) {
 
 // Add assertions to catch common errors when using the Promise object we
 // create on Module.ready() and return from MODULARIZE Module() invocations.
-function addReadyPromiseAssertions(promise) {
+function addReadyPromiseAssertions() {
   // Warn on someone doing
   //
   //  var instance = Module();
@@ -948,8 +948,8 @@ function addReadyPromiseAssertions(promise) {
   const warningEnding = ' on the Promise object, instead of the instance. Use .then() to get called back with the instance, see the MODULARIZE docs in src/settings.js';
   const res = JSON.stringify(properties);
   return res + `.forEach((prop) => {
-  if (!Object.getOwnPropertyDescriptor(${promise}, prop)) {
-    Object.defineProperty(${promise}, prop, {
+  if (!Object.getOwnPropertyDescriptor(readyPromise, prop)) {
+    Object.defineProperty(readyPromise, prop, {
       get: () => abort('You are getting ' + prop + '${warningEnding}'),
       set: () => abort('You are setting ' + prop + '${warningEnding}'),
     });

src/shell.js

@@ -66,12 +66,12 @@ var Module = typeof {{{ EXPORT_NAME }}} != 'undefined' ? {{{ EXPORT_NAME }}} : {
 #if MODULARIZE
 // Set up the promise that indicates the Module is initialized
 var readyPromiseResolve, readyPromiseReject;
-Module['ready'] = new Promise((resolve, reject) => {
+var readyPromise = new Promise((resolve, reject) => {
   readyPromiseResolve = resolve;
   readyPromiseReject = reject;
 });
 #if ASSERTIONS
-{{{ addReadyPromiseAssertions("Module['ready']") }}}
+{{{ addReadyPromiseAssertions() }}}
 #endif
 #endif
 

src/shell_minimal.js

@@ -36,12 +36,12 @@ var Module = {{{ EXPORT_NAME }}};
 #if MODULARIZE && EXPORT_READY_PROMISE
 // Set up the promise that indicates the Module is initialized
 var readyPromiseResolve, readyPromiseReject;
-Module['ready'] = new Promise((resolve, reject) => {
+var readyPromise = new Promise((resolve, reject) => {
   readyPromiseResolve = resolve;
   readyPromiseReject = reject;
 });
 #if ASSERTIONS
-{{{ addReadyPromiseAssertions("Module['ready']") }}}
+{{{ addReadyPromiseAssertions() }}}
 #endif
 #endif
 

tools/link.py

@@ -2312,14 +2312,12 @@ def modularize():
      shared.target_environment_may_be('web'):
     async_emit = 'async '
 
-  # Return the incoming `moduleArg`.  This is is equeivielt to the `Module` var within the
-  # generated code but its not run through closure minifiection so we can reference it in
-  # the the return statement.
-  return_value = 'moduleArg'
   if settings.WASM_ASYNC_COMPILATION:
-    return_value += '.ready'
-  if not settings.EXPORT_READY_PROMISE:
-    return_value = '{}'
+    return_value = 'readyPromise'
+    if not settings.EXPORT_READY_PROMISE:
+      return_value = '{}'
+  else:
+    return_value = 'Module'
 
   # TODO: Remove when https://bugs.webkit.org/show_bug.cgi?id=223533 is resolved.
   if async_emit != '' and settings.EXPORT_NAME == 'config':