Remove VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT and VK_MEMORY_PROPERTY_HOST_CACHED_BIT
from MVK_VK_MEMORY_TYPE_METAL_SHARED.
Refactor MVKPhysicalDevice::initMemoryProperties() to configure memory
types and heaps in a more organized, procedural, and traceable manner.
Enhance MVKPhysicalDevice::getHasUnifiedMemory() detection of unified memory.
Simplify MVKPhysicalDevice::getVRAMSize().
On macOS MVKImage::validateUseTexelBuffer() tests the underlying device memory
directly to determine if it has coherent memory and cannot support texel buffer.
Add MVKInstance::getPhysicalDeviceCount().
Add mvkClear() template function for clearing structs and replace use of
memset(*, 0, sz) with mvkClear().
Refactor mvkCopyStruct() and rename to mvkCopy().
574e92a38a