Updated clone for D48116 by Nikolai, now also adds the clang driver flag and the test for it.
If clang has plugins they are also affected by this filtering.
Depending on the included files and the used warning flags, e.g. -
Weverything, a huge number of warnings can be reported for included
files. As processing that many diagnostics comes with a performance
impact and not all clients are interested in those diagnostics, add a
flag to skip them.