Set CMAKE_CXX_FLAGS explicitly when running cmake for libcxx so that we include both the clang and musl include directories. A separate switch already handles the libcxxabi includes. Explicitly disable the libcxx benchmarks: they're not necessary for the docker image. Factor out repeated use of the clang include path as $clang_include.
Some rld changes seem to have become mixed up in this code review. I don't know why :-(. Please ignore them.
Set CMAKE_CXX_FLAGS explicitly when running cmake for libcxx so that we include both the clang and musl include directories. A separate switch already handles the libcxxabi includes. Explicitly disable the libcxx benchmarks: they're not necessary for the docker image. Factor out repeated use of the clang include path as $clang_include.
Some rld changes seem to have become mixed up in this code review. I don't know why :-(. Please ignore them.