Fix special platforms delegation
The toolchain files that create platform aliases for other platforms (like x86_64_v2-centos7-gcc10-opt
is an alias to LCG x86_64-centos7-gcc10-opt
), cannot be aliased as it was done for the special gcc10+dd4hep
cases.
This MR fixes the LCG 101 gcc10+dd4hep
aliases and modifies the generator script to allow this kind of double aliasing in the future.
I also updated the generator to include the fix added manually in !72 (merged).