Let threads joining main finish when main ends

src/jvm.ts

@@ -1360,14 +1360,15 @@ export class JVM {
         // nothing left to report to
       }
     }
+    // Main must be joinable before DestroyJavaVM waits for other threads.
+    yield* this.exitThread(t);
     // DestroyJavaVM: wait for the other non-daemon threads, then shut down.
     while (this.nonDaemonAlive(t)) {
       yield t.block(new Promise<void>((r) => {
         const check = () => (this.nonDaemonAlive(t) ? setTimeout(check, 5) : r());
         check();
       }));
     }
-    yield* this.exitThread(t);
     yield t.call(boot("java/lang/Shutdown").methodMap.get("shutdown()V")!);
     this.halt(code);
   }

test/java/MainThreadExit.java

@@ -0,0 +1,15 @@
+public class MainThreadExit {
+    public static void main(String[] args) {
+        Thread main = Thread.currentThread();
+        main.setUncaughtExceptionHandler((thread, error) -> System.out.println("uncaught: " + error.getMessage()));
+        new Thread(() -> {
+            try {
+                main.join();
+                System.out.println("main alive: " + main.isAlive());
+            } catch (InterruptedException e) {
+                throw new AssertionError(e);
+            }
+        }).start();
+        throw new RuntimeException("main failed");
+    }
+}

test/jtreg/passing.txt

@@ -1053,6 +1053,7 @@ java/lang/Thread/SleepSanity.java
 java/lang/Thread/SleepWithDuration.java
 java/lang/Thread/ThreadStateTest.java
 java/lang/Thread/ThreadStopTest.java
+java/lang/Thread/UncaughtExceptionsTest.java
 java/lang/Thread/virtual/Collectable.java
 java/lang/Thread/virtual/Locking.java
 java/lang/Thread/virtual/Reflection.java