Mark some tests as XFAIL with GCC due to compiler bugs

llvm-svn: 258284
diff --git a/libcxxabi/test/catch_member_function_pointer_01.pass.cpp b/libcxxabi/test/catch_member_function_pointer_01.pass.cpp
index 28b13cc..9b81730 100644
--- a/libcxxabi/test/catch_member_function_pointer_01.pass.cpp
+++ b/libcxxabi/test/catch_member_function_pointer_01.pass.cpp
@@ -7,6 +7,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+// GCC incorrectly allows PMF type "void (T::*)()" to be caught as "void (T::*)() const"
+// See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69375
+// XFAIL: gcc
 #include <cassert>
 
 struct A