Release for Vulkan SDK 1.3.231

• Add support for Vulkan 1.2.
• Add support for extensions:
  • VK_KHR_shader_float_controls
  • VK_KHR_spirv_1_4
• Vulkan semaphore functional improvements:
  • Replace use of MTLFence with an option to limit to a single Vulkan queue and use Metal's implicit submisison order guarantees.
  • Support option to force use of MTLEvents for Vulkan semaphores on NVIDIA and Rosetta2.
  • MVKConfiguration replace booleans semaphoreUseMTLEvent and semaphoreUseMTLFence with enumerated semaphoreSupportStyle.
• Support config option to automatically use Metal argument buffers when VK_EXT_descriptor_indexing
  extension is enabled. MVKConfiguration::useMetalArgumentBuffers (MVK_CONFIG_USE_METAL_ARGUMENT_BUFFERS)
  is now an enum field. The use of Metal argument buffers is still disabled by default (MVK_CONFIG_USE_METAL_ARGUMENT_BUFFERS_NEVER).
• Fix memory leaks when configured for prefilling Metal command buffers.
• MVKConfiguration replace boolean prefillMetalCommandBuffers with enumeration.
• MVKPipeline: Add builtins that are read but not written to tessellation pipelines.
• Fix occassional crash from retention of MVKSwapchain for future drawable presentations.
• Fix crash in vkCreateSwapchainKHR() on macOS 10.14 and earlier
• Fix undefined reference to vkGetBufferDeviceAddressEXT when building with MVK_HIDE_VULKAN_SYMBOLS=1.
• Update Makefile to forward any build setting declared on the command line to Xcode.
• Add non-functional Vulkan 1.3 core function stubs, to avoid link errors with some external
  libraries that assume Vulkan 1.3 linkages from the standard Vulkan header files included with MoltenVK.
• Add MVK_USE_CEREAL build setting to avoid use of Cereal external library (for pipeline caching).
• MoltenVKShaderConverter tool automatically maps bindings when converting GLSL.
• Update VK_MVK_MOLTENVK_SPEC_VERSION to version 36.
• Update to latest SPIRV-Cross:
  • MSL: Support OpPtrEqual, OpPtrNotEqual, and OpPtrDiff.
  • MSL: Emit correct address space when casting during OpStore.
  • MSL: Add a mechanism to fix up shader outputs.
  • MSL: Handle descriptor aliasing of raw buffer descriptors.
  • MSL: Do not attempt to alias push constants.
  • MSL: only fix up gl_FragCoord if really necessary.
  • MSL: Expose way to query if a buffer needs array length.
  • MSL: Report unsupported 64-bit atomics.
  • Don't rename remapped variables like gl_LastFragDepthARM