cmake.xml: recognize sub-commands of `$<LIST:…>` and `$<PATH:…>` genex
CMake 3.24 has introduced a new ("complex") type of generator expression: $<PATH:…>
. The difference to any other genex 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.