This can be used to disable multibuilds for certain compilers.

This avoids having to install two separate intel_parallel_studio
packages. It is probably also not a good idea anyway to inter-link two
of them at the same time.

According to its own file

  include/crt/host_config.h

This reverts commit 7396fc84.

This turns a package into a branch of another package, after the fact.

Do not filter Compiler for CUDA repositories, they have a fixed
relationship, change macro semantic somewhat, add have_* macros