Hermetic modules with flang

[ivan-pi]

Flang contains this great new feature called hermetic modules files:
https://flang.llvm.org/docs/ModFiles.html#hermetic-modules-files

This could be used to keep only mpi_f08 (and mpi) public in case of binary distribution.

[jeffhammond]

Sounds like a good idea although I'm not really worried about a closed source derivative of Vapaa.

[ivan-pi]

The main benefit I see is you don't have to install a dozen .mod files, but just mpi_f08.mod and libvapaa.a. Nice and clean.