* Bump API patch number and header version number to 64 for this update.
Github Issues:
* Add chapter name to the PDF page footer (public pull request 458).
* Fix several mistaken references to the nonexistent etext:VK_DEVICE_LOST
status to etext:VK_ERROR_DEVICE_LOST (public pull request 502).
* Fix description of the tlink:PFN_vkDebugReportCallbackEXT debug report
callback function pointer to match the validation layer behavior (public
issue 534).
* Document experimental KHX extensions and alternate vendor author IDs
also ending in X in more detail in the <<extensions, Layers &
Extensions>> appendix, the extensions section of the style guide, and
the registry schema description document (public issues 536, 580).
* Fix references to ptext:pDepthStencil to properly refer to
pname:pDepthStencilState or pname:pRasterizationState as appropriate in
the slink:VkGraphicsPipelineCreateInfo description (public issue 542).
* Fix wrong parameter name in slink:VkPipelineMultisampleStateCreateInfo
valid usage (public pull request 571).
Internal Issues:
* Update the style guide to describe how to write LaTeX math expressions
in table cells (internal issue 908).
* Define how framebuffer-local dependencies work between subpasses with
the same or different numbers of samples, in the
slink:VkSubpassDescription and <<synchronization-framebuffer-regions,
Framebuffer Region Dependencies>> sections. This clarifies which samples
in an input attachment you are allowed to access after a
framebuffer-local dependency (internal issue 915).
* Specify which storage classes can have an initializer in the
<<spirvenv-module-validation, Validation Rules within a Module>> section
(internal issue 1023).
* Use "LOD" consistently for "level-of-detail", to eliminate spelling
inconsistencies. The term is already standardized in the Glossary
(internal issue 1027).
Other Issues:
* Fix false positives in Makefile dependencies when rules fail, by
deleting partially-made targets.
New Extensions:
* `VK_AMD_shader_info`