This corresponds to the g++ and clang++
option -fvisibility-inlines-hidden on linux. On Windows with MinGW,
this corresponds to -fno-keep-inline-dllexport. That option is
not supported by clang currently.
While Clang presents an almost identical interface to GNU there will be
some differences. Split the compiler information modules to allow
separate rules for Clang. Start by loading the GNU rules but leave a
place to add Clang-specific information.
Map to the platform and compiler information for GNU because the
compilers are command-line compatible for common operations. Later we
can add Clang-specific features as necessary. We honor the preferred
capitalization is "Clang", not the common mis-spelling "CLang".
Stephen Kelly
Brad King