[C++] clang HEAD 9.0.0 (https://github.com/llvm-mirror/clang.git b6fd974d25c1fc3eb53d1f13d4028b3cde33dd6e) (https://github.com/llvm-mirror/llvm.git dc14d72264ef5a37fcc5266b2fba4d684653e9ec)