fixup! fix libc++ unique_ptr formatter

Author: Michael137

lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp

@@ -528,10 +528,9 @@ lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::Update() {
     if (deleter_sp)
       m_deleter_sp = deleter_sp->Clone(ConstString("deleter"));
   } else {
-    // TODO: with the new layout, deleter is always a member, so empty deleters
-    // will be displayed
     m_value_ptr_sp = ptr_sp->Clone(ConstString("pointer"));
-    m_deleter_sp = deleter_sp->Clone(ConstString("deleter"));
+    if (deleter_sp->GetNumChildrenIgnoringErrors() > 0)
+      m_deleter_sp = deleter_sp->Clone(ConstString("deleter"));
   }
 
   return lldb::ChildCacheState::eRefetch;

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/unique_ptr/TestDataFormatterLibcxxUniquePtr.py

@@ -45,7 +45,6 @@ def test_unique_ptr_variables(self):
             "up_empty",
             type=self.make_expected_type("int"),
             summary="nullptr",
-            #children=[ValueCheck(name="pointer"), ValueCheck(name="deleter")], # TODO: shouldn't be printing deleter
             children=[ValueCheck(name="pointer")],
         )
         self.assertEqual(
@@ -60,7 +59,6 @@ def test_unique_ptr_variables(self):
             "up_int",
             type=self.make_expected_type("int"),
             summary="10",
-            #children=[ValueCheck(name="pointer"), ValueCheck(name="deleter")], # TODO: shouldn't be printing deleter
             children=[ValueCheck(name="pointer")],
         )
         self.assertNotEqual(valobj.child[0].unsigned, 0)
@@ -69,7 +67,6 @@ def test_unique_ptr_variables(self):
             "up_int_ref",
             type=self.make_expected_type("int", qualifiers="&"),
             summary="10",
-            #children=[ValueCheck(name="pointer"), ValueCheck(name="deleter")], # TODO: shouldn't be printing deleter
             children=[ValueCheck(name="pointer")],
         )
         self.assertNotEqual(valobj.child[0].unsigned, 0)
@@ -78,7 +75,6 @@ def test_unique_ptr_variables(self):
             "up_int_ref_ref",
             type=self.make_expected_type("int", qualifiers="&&"),
             summary="10",
-            #children=[ValueCheck(name="pointer"), ValueCheck(name="deleter")], # TODO: shouldn't be printing deleter
             children=[ValueCheck(name="pointer")],
         )
         self.assertNotEqual(valobj.child[0].unsigned, 0)
@@ -87,7 +83,6 @@ def test_unique_ptr_variables(self):
             "up_str",
             type=self.make_expected_basic_string_ptr(),
             summary='"hello"',
-            #children=[ValueCheck(name="pointer"), ValueCheck(name="deleter")], # TODO: shouldn't be printing deleter
             children=[ValueCheck(name="pointer")],
         )