v3dv: expose VK_EXT_load_store_op_none

This extension adds new NONE attachment load / store operations,
which are identical to the DONT_CARE variants with the difference
that DONT_CARE doesn't ensure that the original contents of the
memory within the render area are preserved and these new versions
do (with some caveats).

Our implementation was not destroying data with DONT_CARE anyway
so we already support the new semantics. Our implementation is
such that we don't need to do anything specific with the new
operations and the current behavior will do what is expected.

We pass all the tests under:
dEQP-VK.renderpass*.load_store_op_none.*

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18570>

docs/features.txt

@@ -561,7 +561,7 @@ Khronos extensions that are not part of any Vulkan version:
   VK_EXT_image_view_min_lod                             DONE (anv, radv, tu, vn)
   VK_EXT_index_type_uint8                               DONE (anv, lvp, panvk, radv/gfx8+, v3dv, tu, vn)
   VK_EXT_line_rasterization                             DONE (anv, lvp, radv, tu, v3dv, vn)
-  VK_EXT_load_store_op_none                             DONE (radv, tu)
+  VK_EXT_load_store_op_none                             DONE (radv, tu, v3dv)
   VK_EXT_memory_budget                                  DONE (anv, radv, tu, v3dv)
   VK_EXT_memory_priority                                DONE (radv)
   VK_EXT_multi_draw                                     DONE (anv, lvp, radv, tu)

src/broadcom/vulkan/v3dv_device.c

@@ -171,6 +171,7 @@ get_device_extensions(const struct v3dv_physical_device *device,
       .EXT_color_write_enable               = true,
       .EXT_custom_border_color              = true,
       .EXT_depth_clip_control               = true,
+      .EXT_load_store_op_none               = true,
       .EXT_inline_uniform_block             = true,
       .EXT_external_memory_dma_buf          = true,
       .EXT_host_query_reset                 = true,