clang/test/Index/comment-custom-block-command.cpp: This has not been failing since r175892 on valgrind.
That said, it fails with --vg-leak. Mark it as XFAIL: vg_leak instead.
clang/include/clang/AST/ExprCXX.h:260:5: Fix a warning -- unknown command tag name 'cc'; did you mean 'c'? [-Wdocumentation]