bpo-21263: Skip test_gdb when python has been compiled with LLVM clang (GH-10318)

diff --git a/Lib/test/test_gdb.py b/Lib/test/test_gdb.py
index 0f950b2..711fb69 100644
--- a/Lib/test/test_gdb.py
+++ b/Lib/test/test_gdb.py
@@ -5,6 +5,7 @@
 
 import locale
 import os
+import platform
 import re
 import subprocess
 import sys
@@ -48,6 +49,10 @@
 if not sysconfig.is_python_build():
     raise unittest.SkipTest("test_gdb only works on source builds at the moment.")
 
+if 'Clang' in platform.python_compiler() and sys.platform == 'darwin':
+    raise unittest.SkipTest("test_gdb doesn't work correctly when python is"
+                            " built with LLVM clang")
+
 # Location of custom hooks file in a repository checkout.
 checkout_hook_path = os.path.join(os.path.dirname(sys.executable),
                                   'python-gdb.py')