[lldb][test] Skip pointer to std::unordered_map formatter tests on older Clang versions

These only work after #143501 and #144517. Skip on older compilers. This currently fails on the macOS matrix bots that run the LLDB test-suite with older Clang versions.

See #146040.

Author: Michael137

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/unordered_map-iterator/TestDataFormatterLibccUnorderedMap.py

@@ -105,7 +105,21 @@ def test_iterator_formatters(self):
             type="const StringMapT *const &",
         )
 
-        lldbutil.continue_to_breakpoint(process, bkpt)
+    @expectedFailureAll(
+        bugnumber="https://github.com/llvm/llvm-project/issues/146040",
+        compiler="clang",
+        compiler_version=["<", "21"],
+    )
+    @add_test_categories(["libc++"])
+    def test_ptr_formatters(self):
+        """
+        Test that pointers to std::unordered_map are formatted correctly.
+        """
+
+        self.build()
+        (self.target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, "Stop here", lldb.SBFileSpec("main.cpp", False)
+        )
 
         self.check_ptr_or_ref("ptr1")
         self.check_ptr_or_ref("ptr2")

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/unordered_map-iterator/main.cpp

@@ -16,7 +16,7 @@ static void check_references(const StringMapT &ref1, StringMapT &ref2,
 static void check_pointer(const StringMapT *ptr1, StringMapT *ptr2,
                           StringMapTPtr ptr3, StringMapTPtr *ptr4,
                           const StringMapT *const *ptr5, StringMapT **ptr6) {
-  std::printf("Break here");
+  std::printf("Stop here");
 }
 
 int main() {