Revert "Temporarily remove three newly added tests"

This reverts commit 24ebb03.

t/nqp/100-dispatcher.t

@@ -1,4 +1,4 @@
-plan(7);
+plan(10);
 my $closure;
 {
     nqp::setdispatcher(100);
@@ -60,3 +60,22 @@ nqp::setdispatcherfor(400, $wraped2);
 $wraped1();
 $wraped2();
 
+sub take_or_clear($take) {
+    my $foo := 100;
+    if $take {
+      nqp::takedispatcher('$foo');
+    } else {
+      nqp::cleardispatcher();
+    }
+    $foo;
+}
+
+if nqp::getcomp('nqp').backend.name eq 'jvm' {
+    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);
+} else {
+    skip('skip broken tests on the jvm', 3);
+}