v3dv: implement workaround for GFXH-1461

If a subpass clears one aspect of Depth/Stencil but loads the other
the clear might get lost. Fix this by emitting the clear as a draw
call instead of relying on the TLB clear.

Fixes:
dEQP-VK.renderpass.suballocation.attachment.3.307

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>
3 files changed