CMake does but I think you have to attempt a build to get the database. On the other hand I don't think that should be necessary, as it is capable of generating Ninja build files.

Almost nobody is writing Ninja files by hand. If you have to write something along those lines by hand, Makefiles would make more sense than Ninja. If Ninja does support exporting commands, it's a use case that doesn't matter because almost everyone uses CMake-generated Ninja files.