Resolve test failures

By always calling `emscripten_main_thread_process_queued_calls()` before `emscripten_futex_wait()`.

Author: kleisauke

system/lib/libc/musl/src/thread/__timedwait.c

@@ -78,15 +78,18 @@ int __timedwait_cp(volatile int *addr, int val,
 				// cancel execution.
 				return ECANCELED;
 			}
-			if (msecsToSleep > 0)
-				// Must wait in slices in case this thread is cancelled in between.
-				r = -emscripten_futex_wait((void*)addr, val,
-					msecsToSleep > max_ms_slice_to_sleep ? max_ms_slice_to_sleep : msecsToSleep);
 			// Assist other threads by executing proxied operations that are effectively singlethreaded.
 			if (is_runtime_thread) emscripten_main_thread_process_queued_calls();
 
 			msecsToSleep = sleepUntilTime - emscripten_get_now();
-		} while (r == ETIMEDOUT && msecsToSleep > 0);
+			if (msecsToSleep <= 0) {
+				r = ETIMEDOUT;
+				break;
+			}
+			// Must wait in slices in case this thread is cancelled in between.
+			r = -emscripten_futex_wait((void*)addr, val,
+				msecsToSleep > max_ms_slice_to_sleep ? max_ms_slice_to_sleep : msecsToSleep);
+		} while (r == ETIMEDOUT);
 	} else {
 		// Can wait in one go.
 		r = -emscripten_futex_wait((void*)addr, val, msecsToSleep);

system/lib/libc/musl/src/thread/__wait.c

@@ -28,10 +28,10 @@ void __wait(volatile int *addr, volatile int *waiters, int val, int priv)
 					if (waiters) a_dec(waiters);
 					return;
 				}
-				// Must wait in slices in case this thread is cancelled in between.
-				e = emscripten_futex_wait((void*)addr, val, max_ms_slice_to_sleep);
 				// Assist other threads by executing proxied operations that are effectively singlethreaded.
 				if (is_runtime_thread) emscripten_main_thread_process_queued_calls();
+				// Must wait in slices in case this thread is cancelled in between.
+				e = emscripten_futex_wait((void*)addr, val, max_ms_slice_to_sleep);
 			} while (e == -ETIMEDOUT);
 		} else {
 			// Can wait in one go.