Genex: Simplify the preprocessor looper for interface properties.

By removing the INTERFACE_ prefix, we can use this in more contexts.
Genex: Use a preprocessor foreach to follow transitive properties.
Merge topic 'pp-transitive-property-handling' into next

26f1a91 Genex: Use a preprocessor foreach to follow transitive properties.
6ceb097 Genex: Simplify the preprocessor looper for interface properties.