fix: Crash during PThread initialization on big-endian machine

src/lib/libpthread.js

@@ -143,7 +143,7 @@ var LibraryPThread = {
 
     threadStatusAsString(pthreadPtr) {
       var profilerBlock = {{{ makeGetValue('pthreadPtr', C_STRUCTS.pthread.profilerBlock, '*') }}};
-      var status = (profilerBlock == 0) ? 0 : Atomics.load(HEAPU32, {{{ getHeapOffset('profilerBlock + ' + C_STRUCTS.thread_profiler_block.threadStatus, 'i32') }}});
+      var status = (profilerBlock == 0) ? 0 : (nativeByteOrder32(Atomics.load(HEAPU32, {{{ getHeapOffset('profilerBlock + ' + C_STRUCTS.thread_profiler_block.threadStatus, 'i32') }}})) >>> 0);
       return PThread.threadStatusToString(status);
     },
 #endif
@@ -1228,13 +1228,13 @@ var LibraryPThread = {
       // safe to access from sending threads that need to notify the waiting
       // thread.
       // TODO: How to make this work with wasm64?
-      var wait = Atomics.waitAsync(HEAP32, {{{ getHeapOffset('pthread_ptr', 'i32') }}}, pthread_ptr);
+      var wait = Atomics.waitAsync(HEAP32, {{{ getHeapOffset('pthread_ptr', 'i32') }}}, nativeByteOrder32(pthread_ptr));
 #if ASSERTIONS
       assert(wait.async);
 #endif
       wait.value.then(checkMailbox);
       var waitingAsync = pthread_ptr + {{{ C_STRUCTS.pthread.waiting_async }}};
-      Atomics.store(HEAP32, {{{ getHeapOffset('waitingAsync', 'i32') }}}, 1);
+      Atomics.store(HEAP32, {{{ getHeapOffset('waitingAsync', 'i32') }}}, nativeByteOrder32(1));
     }
     // If `Atomics.waitAsync` is not implemented, then we will always fall back
     // to postMessage and there is no need to do anything here.

src/runtime_shared.js

@@ -83,6 +83,19 @@ function updateMemoryViews() {
 #endif
 }
 
+#if SUPPORT_BIG_ENDIAN
+var nativeByteOrder32 = (() => {
+    var h16 = new Int16Array(1);
+    var h8 = new Int8Array(h16.buffer);
+    h16[0] = 42;
+    return h8[0] === 42 && h8[1] === 0; // little endian ordering
+  })()
+  /* little endian */ ? (v => v)
+  /*    big endian */ : (v => ((v >> 24) & 0xff) | ((v >> 8) & 0xff00) | ((v & 0xff00) << 8) | ((v & 0xff) << 24));
+#else
+var nativeByteOrder32 = (v => v);
+#endif
+
 #if ENVIRONMENT_MAY_BE_NODE && MIN_NODE_VERSION < 160000
 // The performance global was added to node in v16.0.0:
 // https://nodejs.org/api/globals.html#performance