file_packager: Fix regression in --separate-metadata output (#22802)

This reverts commit 483cdcd.

This also adds some testing of the `--separate-metadata` file_packager
options where we actually run the generated code. As part of adding this
test I also made the code work under node.

Fixes: #22790

Author: sbc100

src/library.js

@@ -1946,8 +1946,10 @@ addToLibrary({
 
   $callRuntimeCallbacks__internal: true,
   $callRuntimeCallbacks: (callbacks) => {
-    // Pass the module as the first argument.
-    callbacks.forEach((f) => f(Module));
+    while (callbacks.length > 0) {
+      // Pass the module as the first argument.
+      callbacks.shift()(Module);
+    }
   },
 
 #if SHRINK_LEVEL == 0 || ASYNCIFY == 2

src/postamble.js

@@ -27,7 +27,6 @@ if (ENVIRONMENT_IS_WORKER) {
 {{{ exportRuntime() }}}
 
 var calledRun;
-var calledPrerun;
 
 #if STANDALONE_WASM && MAIN_READS_PARAMS
 var mainArgs = undefined;
@@ -47,7 +46,7 @@ function callMain() {
 #endif
 #if ASSERTIONS
   assert(runDependencies == 0, 'cannot call main when async dependencies remain! (listen on Module["onRuntimeInitialized"])');
-  assert(calledPrerun, 'cannot call main without calling preRun first');
+  assert(__ATPRERUN__.length == 0, 'cannot call main when preRun functions remain to be called');
 #endif
 
   var entryFunction = {{{ getEntryFunction() }}};
@@ -189,25 +188,22 @@ function run() {
   stackCheckInit();
 #endif
 
-  if (!calledPrerun) {
-    calledPrerun = 1;
-    preRun();
+  preRun();
 
-    // a preRun added a dependency, run will be called later
-    if (runDependencies > 0) {
+  // a preRun added a dependency, run will be called later
+  if (runDependencies > 0) {
 #if RUNTIME_DEBUG
-      dbg('run() called, but dependencies remain, so not running');
+    dbg('run() called, but dependencies remain, so not running');
 #endif
-      return;
-    }
+    return;
   }
 
   function doRun() {
     // run may have just been called through dependencies being fulfilled just in this very frame,
     // or while the async setStatus time below was happening
     if (calledRun) return;
-    calledRun = 1;
-    Module['calledRun'] = 1;
+    calledRun = true;
+    Module['calledRun'] = true;
 
     if (ABORT) return;
 

src/preamble.js

@@ -195,10 +195,11 @@ function preRun() {
   assert(!ENVIRONMENT_IS_PTHREAD); // PThreads reuse the runtime from the main thread.
 #endif
 #if expectToReceiveOnModule('preRun')
-  var preRuns = Module['preRun'];
-  if (preRuns) {
-    if (typeof preRuns == 'function') preRuns = [preRuns];
-    preRuns.forEach(addOnPreRun);
+  if (Module['preRun']) {
+    if (typeof Module['preRun'] == 'function') Module['preRun'] = [Module['preRun']];
+    while (Module['preRun'].length) {
+      addOnPreRun(Module['preRun'].shift());
+    }
   }
 #endif
   callRuntimeCallbacks(__ATPRERUN__);
@@ -288,10 +289,11 @@ function postRun() {
 #endif
 
 #if expectToReceiveOnModule('postRun')
-  var postRuns = Module['postRun'];
-  if (postRuns) {
-    if (typeof postRuns == 'function') postRuns = [postRuns];
-    postRuns.forEach(addOnPostRun);
+  if (Module['postRun']) {
+    if (typeof Module['postRun'] == 'function') Module['postRun'] = [Module['postRun']];
+    while (Module['postRun'].length) {
+      addOnPostRun(Module['postRun'].shift());
+    }
   }
 #endif
 

test/other/codesize/test_codesize_cxx_ctors1.gzsize

@@ -1 +1 @@
-8472
+8465

test/other/codesize/test_codesize_cxx_ctors1.jssize

@@ -1 +1 @@
-20767
+20821

test/other/codesize/test_codesize_cxx_ctors2.gzsize

@@ -1 +1 @@
-8453
+8449

test/other/codesize/test_codesize_cxx_ctors2.jssize

@@ -1 +1 @@
-20735
+20789

test/other/codesize/test_codesize_cxx_except.gzsize

@@ -1 +1 @@
-9499
+9487

test/other/codesize/test_codesize_cxx_except.jssize

@@ -1 +1 @@
-24611
+24665

test/other/codesize/test_codesize_cxx_except_wasm.gzsize

@@ -1 +1 @@
-8431
+8427