Add test for nqp::cleardispatcher

Author: pmurias

t/nqp/100-dispatcher.t

@@ -1,4 +1,4 @@
-plan(7);
+plan(10);
 my $closure;
 {
     nqp::setdispatcher(100);
@@ -59,3 +59,19 @@ nqp::setdispatcherfor(400, $wraped2);
 
 $wraped1();
 $wraped2();
+
+sub take_or_clear($take) {
+    my $foo := 100;
+    if $take {
+      nqp::takedispatcher('$foo');
+    } else {
+      nqp::cleardispatcher();
+    }
+    $foo;
+}
+
+nqp::setdispatcherfor(400, &take_or_clear);
+is(take_or_clear(1), 400);
+nqp::setdispatcherfor(400, &take_or_clear);
+is(take_or_clear(0), 100);
+is(take_or_clear(1), 100);