`lfortran` < 1.24 uses `fccn`, a Fortran-to-C converter that
incorrectly handles long filenames that are more than 128 characters
long; so to check if Fortran can compile something, CMake must be
run in binary directory that has a name of less that 35 characters long.
It is ok for typical runs line `cmake -S . -B build` or `cmake ..`,
but does not work with usual CDash dashboard testing paths.
All this is not a problem for modern LCC >= 1.24.
Cases for `CheckSource{Compiles,Runs}` and `Check{Compiler,Linker}Flag`
cover the modules with the language as a parameter, not the
language-specific modules.
