Port the python api decorator to use test categories

Summary:
Per discussions on the mailing list, I have implemented a decorator which annotates individual
test methods with categories. I have used this framework to replace the '-a' and '+a'
command-line switches (now '-G pyapi' and '--skip-category pyapi') and the @python_api_test
decorator (now @add_test_categories('pyapi')). The test suite now gives an error message
suggesting the new options if the user specifies the deprecated +/-a switches. If the general
direction is good, I will follow this up with other switches.

Reviewers: tberghammer, tfiala, granata.enrico, zturner

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D14020

llvm-svn: 251277
diff --git a/lldb/test/lang/cpp/class_static/TestStaticVariables.py b/lldb/test/lang/cpp/class_static/TestStaticVariables.py
index ba770af..5bb5481 100644
--- a/lldb/test/lang/cpp/class_static/TestStaticVariables.py
+++ b/lldb/test/lang/cpp/class_static/TestStaticVariables.py
@@ -52,7 +52,7 @@
     @expectedFailureClang('Clang emits incomplete debug info.')
     @expectedFailureFreeBSD('llvm.org/pr20550 failing on FreeBSD-11')
     @expectedFailureGcc('GCC emits incomplete debug info.')
-    @python_api_test
+    @add_test_categories(['pyapi'])
     def test_with_python_api(self):
         """Test Python APIs on file and class static variables."""
         self.build()