Add __has_feature support for attributes ns_returns_not_retained
and cf_returns_not_retained.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@96538 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index b97ab24..fd67f4c 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -501,8 +501,10 @@
          //.Case("cxx_variadic_templates", false)
            .Case("attribute_ext_vector_type", true)
            .Case("attribute_analyzer_noreturn", true)
-           .Case("attribute_ns_returns_retained", true)
+           .Case("attribute_cf_returns_not_retained", true)
            .Case("attribute_cf_returns_retained", true)
+           .Case("attribute_ns_returns_not_retained", true)
+           .Case("attribute_ns_returns_retained", true)
            .Default(false);
 }