test: Mark 3 tests as XFAIL:cygwin,mingw.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127077 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGenCXX/debug-info-namespace.cpp b/test/CodeGenCXX/debug-info-namespace.cpp
index 2e0a96d..89b03a6 100644
--- a/test/CodeGenCXX/debug-info-namespace.cpp
+++ b/test/CodeGenCXX/debug-info-namespace.cpp
@@ -1,3 +1,4 @@
+// XFAIL: cygwin,mingw
 // RUN: %clang  -g -S %s -o - | FileCheck %s
 
 // CHECK: TAG_namespace