We now choose between two (equal as of this commit) layouts based on
whether the renderpass's stores will use the CCU space, and assert that we
always know the chosen layout when we go using the gmem offsets.
This required making vkCmdClearAttachments in a secondary take the 3D path
instead of gmem blits, since secondaries only have to be compatible with
the primary's renderpass, rather than equal.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16921>