XFAIL the test that is not supported on the branch
rdar://problem/27666416
diff --git a/test/ASTMerge/anonymous-fields.cpp b/test/ASTMerge/anonymous-fields.cpp
index 67afc29..6210142 100644
--- a/test/ASTMerge/anonymous-fields.cpp
+++ b/test/ASTMerge/anonymous-fields.cpp
@@ -1,3 +1,4 @@
+// XFAIL: *
// RUN: %clang_cc1 -emit-pch -o %t.1.ast %S/Inputs/anonymous-fields1.cpp
// RUN: %clang_cc1 -emit-pch -o %t.2.ast %S/Inputs/anonymous-fields2.cpp
// RUN: %clang_cc1 -emit-obj -o /dev/null -ast-merge %t.1.ast -ast-merge %t.2.ast %s
