libpthread.js: Return result from allocateUnusedWorker. NFC (#27015)

Author: sbc100

src/lib/libpthread.js

@@ -545,6 +545,7 @@ var LibraryPThread = {
       worker.workerID = PThread.nextWorkerID++;
 #endif
       PThread.unusedWorkers.push(worker);
+      return worker;
     },
 
     getNewWorker() {
@@ -573,8 +574,8 @@ var LibraryPThread = {
 #endif
 #endif // PTHREAD_POOL_SIZE_STRICT
 #if PTHREAD_POOL_SIZE_STRICT < 2 || ENVIRONMENT_MAY_BE_NODE
-        PThread.allocateUnusedWorker();
-        PThread.loadWasmModuleToWorker(PThread.unusedWorkers[0]);
+        var newWorker = PThread.allocateUnusedWorker();
+        PThread.loadWasmModuleToWorker(newWorker);
 #endif
       }
       return PThread.unusedWorkers.pop();

test/codesize/test_codesize_minimal_pthreads.json

@@ -1,10 +1,10 @@
 {
-  "a.out.js": 7121,
-  "a.out.js.gz": 3528,
+  "a.out.js": 7110,
+  "a.out.js.gz": 3524,
   "a.out.nodebug.wasm": 19037,
   "a.out.nodebug.wasm.gz": 8787,
-  "total": 26158,
-  "total_gz": 12315,
+  "total": 26147,
+  "total_gz": 12311,
   "sent": [
     "a (memory)",
     "b (exit)",

test/codesize/test_codesize_minimal_pthreads_memgrowth.json

@@ -1,10 +1,10 @@
 {
-  "a.out.js": 7529,
-  "a.out.js.gz": 3732,
+  "a.out.js": 7518,
+  "a.out.js.gz": 3728,
   "a.out.nodebug.wasm": 19038,
   "a.out.nodebug.wasm.gz": 8788,
-  "total": 26567,
-  "total_gz": 12520,
+  "total": 26556,
+  "total_gz": 12516,
   "sent": [
     "a (memory)",
     "b (exit)",