Some additional comments:
You will never include a compiler-specific pragmas/ or inline/ file.
proto/regex.h
will include all you need and keeps your source easily portable between different compilers. Also the prototypes in
clib/regex_protos.h
are not needed, as
proto/regex.h
takes care of that as well.
The FD file is only needed if you want to build header files for a currently unsupported compiler.