-trigraphs is now an alias for -ftrigraphs. -fno-trigraphs makes it possible
to explicitly disable trigraphs, which couldn't be done before.
clang -std=c++11 -fno-trigraphs
now builds without GNU extensions, but with trigraphs disabled. Previously,
trigraphs were only disabled in GNU modes or with -std=c++1z.
Make the new -f flags the cc1 interface too. This requires changing -trigraphs
to -ftrigraphs in a few cc1 tests.
Related to PR21974.
llvm-svn: 224790
Nico Weber