Fix wrenAbortFiber does not work inside of foreign class allocator

test/api/foreign_class.c

@@ -82,6 +82,13 @@ static void resourceFinalize(void* data)
   finalized++;
 }
 
+static void badClassAllocate(WrenVM* vm)
+{
+  wrenEnsureSlots(vm, 1);
+  wrenSetSlotString(vm, 0, "Something went wrong");
+  wrenAbortFiber(vm, 0);
+}
+
 WrenForeignMethodFn foreignClassBindMethod(const char* signature)
 {
   if (strcmp(signature, "static ForeignClass.finalized") == 0) return apiFinalized;
@@ -114,4 +121,10 @@ void foreignClassBindClass(
     methods->finalize = resourceFinalize;
     return;
   }
+
+  if (strcmp(className, "BadClass") == 0)
+  {
+    methods->allocate = badClassAllocate;
+    return;
+  }
 }

test/api/foreign_class.wren

@@ -75,3 +75,13 @@ resources.clear()
 
 System.gc()
 System.print(ForeignClass.finalized) // expect: 3
+
+// Class that aborts fiber
+foreign class BadClass {
+  construct new() {}
+}
+
+error = Fiber.new {
+  BadClass.new()
+}.try()
+System.print(error) // expect: Something went wrong