Consistently set 8 MiB stack sizes on all platforms

redwood-treehouse-host/src/androidMain/kotlin/app/cash/redwood/treehouse/AndroidTreehouseDispatchers.kt

@@ -30,7 +30,7 @@ internal class AndroidTreehouseDispatchers : TreehouseDispatchers {
 
   /** The single thread that runs all JavaScript. We only have one QuickJS instance at a time. */
   private val executorService = Executors.newSingleThreadExecutor { runnable ->
-    Thread(runnable, "Treehouse")
+    Thread(null, runnable, "Treehouse", ZIPLINE_THREAD_STACK_SIZE.toLong())
       .also { ziplineThread = it }
   }
 

redwood-treehouse-host/src/commonMain/kotlin/app/cash/redwood/treehouse/TreehouseDispatchers.kt

@@ -54,3 +54,9 @@ public interface TreehouseDispatchers {
    */
   public fun close()
 }
+
+/**
+ * We configure an 8 MiB thread size because we've experimentally found that's sufficient for our
+ * guest programs.
+ */
+internal val ZIPLINE_THREAD_STACK_SIZE = 8 * 1024 * 1024

redwood-treehouse-host/src/iosMain/kotlin/app/cash/redwood/treehouse/IosTreehouseDispatchers.kt

@@ -53,10 +53,8 @@ private class SingleThreadCoroutineDispatcher : CloseableCoroutineDispatcher() {
   /**
    * On Apple platforms we need to explicitly set the stack size for background threads; otherwise
    * we get the default of 512 KiB which isn't sufficient for our QuickJS programs.
-   *
-   * 8 MiB is more than sufficient.
    */
-  private val stackSize = 8 * 1024 * 1024
+  private val stackSize = ZIPLINE_THREAD_STACK_SIZE
   private val channel = Channel<Runnable>(capacity = Channel.UNLIMITED)
 
   val thread = NSThread {