Log Message:
mesa: update to 18.3.4

Bug fixes
  Bug 109107 - gallium/st/va: change va max_profiles when using Radeon VCN Hardware
  Bug 109401 - [DXVK] Project Cars rendering problems
  Bug 109543 - After upgrade mesa to 19.0.0~rc1 all vulkan based application \ 
stop working ["vulkan-cube" received SIGSEGV in \ 
radv_pipeline_init_blend_state at ../src/amd/vulkan/radv_pipeline.c:699]
  Bug 109603 - nir_instr_as_deref: Assertion `parent && parent->type \ 
== nir_instr_type_deref' failed.

Changes
  gallium-xlib: query MIT-SHM before using it.
  radv: Only look at pImmutableSamples if the descriptor has a sampler.
  amd/common: Use correct writemask for shared memory stores.
  get-pick-list: Add --pretty=medium to the arguments for Cc patches
  meson: Add dependency on genxml to anvil
  docs: add sha256 checksums for 18.3.3
  cherry-ignore: nv50,nvc0: add explicit settings for recent caps
  cherry-ignore: add more 19.0 only nominations from Ilia
  cherry-ignore: radv: fix using LOAD_CONTEXT_REG with old GFX ME firmwares on GFX8
  Update version to 18.3.4
  vc4: Fix copy-and-paste fail in backport of NEON asm fixes.
  xvmc: fix string comparison
  xvmc: fix string comparison
  vc4: Fix leak in HW queries error path
  v3d: Fix leak in resource setup error path
  intel/compiler: do not copy-propagate strided regions to ddx/ddy arguments
  nvc0: we have 16k-sized framebuffers, fix default scissors
  intel/fs: Handle IMAGE_SIZE in size_read() and is_send_from_grf()
  intel/fs: Do the grf127 hack on SIMD8 instructions in SIMD16 mode
  nir/deref: Rematerialize parents in rematerialize_derefs_in_use_blocks
  anv/cmd_buffer: check for NULL framebuffer
  st/mesa: Limit GL_MAX_[NATIVE_]PROGRAM_PARAMETERS_ARB to 2048
  freedreno/a6xx: Emit blitter dst with OUT_RELOCW
  st/va: fix the incorrect max profiles report
  st/va/vp9: set max reference as default of VP9 reference number
  meson: drop the xcb-xrandr version requirement
  gallium/u_threaded: fix EXPLICIT_FLUSH for flush offsets > 0
  radeonsi: fix EXPLICIT_FLUSH for flush offsets > 0
  winsys/amdgpu: don't drop manually added fence dependencies
  egl/wayland: Allow client->server format conversion for PRIME offload. (v2)
  egl/wayland-drm: Only announce formats via wl_drm which the driver supports.
  radeonsi: Fix guardband computation for large render targets
  freedreno: stop frob'ing pipe_resource::nr_samples
  intel: Add more PCI Device IDs for Coffee Lake and Ice Lake.
  radv: fix compiler issues with GCC 9
  radv: always export gl_SampleMask when the fragment shader uses it