linux-kpi/drm_shim.rs previously tracked GEM objects only in a local
HashMap. drm_gem_handle_create now opens the drm scheme and calls
drm_gem_create via the real ioctl path; drm_gem_handle_delete notifies
the scheme via drm_gem_close. Added write_size, scheme_ioctl, and
ensure_scheme_fd helpers. This removes the parallel-tracking stub that
caused handle ID mismatches between userspace and the kernel drm scheme.
Cross-referenced with Linux drivers/gpu/drm/drm_gem.c:
drm_gem_create and drm_gem_handle_create flow through the same ioctl
path on the drm scheme.
vasilito
9676023c4b