The culling tests could be changed only with the console's
structure_culling, which did not last past the game's end. The setting
(HALO_STRUCTURE_CULLING) gives the starting bits, 31 (every test) by
default as before, read in render_initialize; the console command still
changes them while the game runs. Documented in the settings table.
Checked: tools/harness (640 passed, the structure culling tests among
them), test_linux_port's config section and menu settings tests, and the
changed files compiled with -fsyntax-only for Linux, the Android guest
and the web.