FROMLIST: anv: Add support for the variablePointers feature

Not to be confused with variablePointersStorageBuffer which is the
subset of VK_KHR_variable_pointers required to enable the extension.
This means we now have "full" support for variable pointers.

Archived-At: https://lists.freedesktop.org/archives/mesa-dev/2017-October/173537.html
(am from https://patchwork.freedesktop.org/patch/183830/)

Needed for SPIR-V VariablePointers capability.

Testing:
  Tests for this feature were released in Vulkan CTS 1.0.2.4 on
  2017-07-11, and were later merged into the oreo branches of deqp. But
  in that release some testcases were buggy, causing some drivers to
  crash. In particular, the bugs crashed Anvil. All but one of the
  required fixes have landed in vk-gl-cts master@e52de55c. The last
  fix is still under review in Khronos's internal Gerrit as
  https://gerrit.khronos.org/#/c/1864/. I've pushed a public vk-gl-cts
  branch[1] containing the remaining fix, and tagged[2] the vk-gl-cts
  commit I tested against. Likewise for Mesa, I tagged[3] the commit
  I tested, based on branch cros/arc-17.3.

  Android is hard. Running the Oreo CTS on Nougat is even harder.
  I confirmed that some testcases for this feature passed when running
  the Oreo CTS on ARC++ Nougat, though the CTS eventually crashed due to
  the reasons explained above.

  I verified everything on Fedora instead. All 949 of the following
  tests passed:

  dEQP-VK.spirv_assembly.instruction.compute.variable_pointers.*
  dEQP-VK.spirv_assembly.instruction.graphics.variable_pointers.*

  [1]: http://git.kiwitree.net/cgit/~chadv/vk-gl-cts/log/?h=fixes/spirv-variable-pointers
  [2]: http://git.kiwitree.net/cgit/~chadv/vk-gl-cts/log/?h=chadv/test/spirv-variable-pointers-2017-11-29
  [3]: http://git.kiwitree.net/cgit/~chadv/mesa/log/?h=chadv/test/arc-17.3-anv-variable-pointers-2017-11-29

BUG=b:68708929
TEST=No regressions on Eve in `cts-tradefed run cts -m CtsDeqpTestCases`.

Change-Id: I93f94a0d5f976575826397d60b42d3b11a919269
Reviewed-on: https://chromium-review.googlesource.com/799681
Tested-by: Chad Versace <chadversary@chromium.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@chromium.org>
Commit-Queue: Kristian H. Kristensen <hoegsberg@chromium.org>
2 files changed