* Bump API patch number and header version number to 42 for this update
(the first anniversary edition).
Github Issues:
* Changed asciidoctor macros so cross-page links in the standalone
reference pages function properly (public issue 462).
Internal Issues:
* Clarified host visibility discussion for slink:VkMemoryType,
flink:vkInvalidateMappedMemoryRanges, elink:VkAccessFlagBits, and the
<<synchronization-framebuffer-regions,Framebuffer Region Dependencies>>
section, removing duplicated information and adding a central definition
in the access types section (internal issue 552).
* Change description of
slink:vkGetPhysicalDeviceSurfacePresentModesKHR::pname:pPresentModes to
return an array of values, not structures (internal issue 699).
New Extensions:
* Add a NOTE to the <<extensions,Layers & Extensions>> chapter describing
the experimental status of `KHX` extensions.
* Add new Khronos, Khronos Experimental, and vendor Vulkan extensions for
release at GDC:
** VK_KHR_descriptor_update_template
** VK_KHR_push_descriptor
** VK_KHX_device_group
** VK_KHX_device_group_creation
** VK_KHX_external_memory
** VK_KHX_external_memory_capabilities
** VK_KHX_external_memory_fd
** VK_KHX_external_memory_win32
** VK_KHX_external_semaphore
** VK_KHX_external_semaphore_capabilities
** VK_KHX_external_semaphore_fd
** VK_KHX_external_semaphore_win32
** VK_KHX_multiview
** VK_KHX_win32_keyed_mutex
** VK_EXT_discard_rectangles
** VK_MVK_ios_surface
** VK_MVK_macos_surface
** VK_NVX_multiview_per_view_attributes
** VK_NV_clip_space_w_scaling
** VK_NV_geometry_shader_passthrough
** VK_NV_sample_mask_override_coverage
** VK_NV_viewport_array2
** VK_NV_viewport_swizzle
* Add new GLSL vendor extensions to support new builtin variables:
** GL_EXT_device_group
** GL_EXT_multiview
Jon Leech