Make pending_interrupt?(Exception) work

A patch from katsu (Katsuhiro Ueno)

[Bug #19110]

test/ruby/test_thread.rb

@@ -1515,4 +1515,12 @@ q.pop
       end
     };
   end
+
+  def test_pending_interrupt?
+    t = Thread.handle_interrupt(Exception => :never) { Thread.new { Thread.stop } }
+    t.raise(StandardError)
+    assert_equal(true, t.pending_interrupt?)
+    assert_equal(true, t.pending_interrupt?(Exception))
+    assert_equal(false, t.pending_interrupt?(ArgumentError))
+  end
 end

thread.c

@@ -1922,7 +1922,7 @@ rb_threadptr_pending_interrupt_include_p(rb_thread_t *th, VALUE err)
     int i;
     for (i=0; i<RARRAY_LEN(th->pending_interrupt_queue); i++) {
         VALUE e = RARRAY_AREF(th->pending_interrupt_queue, i);
-        if (rb_class_inherited_p(e, err)) {
+        if (rb_obj_is_kind_of(e, err)) {
             return TRUE;
         }
     }