[CMake] Compaq Visual Fortran (was: What's the best way to support additional compilers for an "official" CMake language such as Fortran)

[Brad King]

Brad King wrote:
> As a first step, we can add Compaq to CMakeFortranCompilerId.F.in.
> What is the preprocessor macro that identifies it?

I'd like to teach CMake upstream to recognize the Compaq Fortran
compiler even if we do not provide platform files for it yet.
CMake already recognizes the Compaq C and C++ compilers using
the macros __DECC and __DECCXX, respectively.

(1) What macro identifies the Compaq Fortran compiler?

(2) Does the compiler need a special option to preprocess a source
    with the extension ".F" (e.g. /fpp)?

Thanks,
-Brad