cmake.xml: recognize sub-commands of `$<LIST:…>` and `$<PATH:…>` genex

CMake 3.24 has introduced new ("complex") type of generator expression: `$<PATH:…>`.
The difference to any other genex before is that it has a "sub-command" as the
first "argument".

CMake 3.27 has added one more such genex: `$<LIST:…>`.

This patch adds recognition of the fist argument of such ("complex") genexes.