Log Message:
parallel/spirv-headers: import SPIRV-Headers-1.2.198.0

This package contains machine-readable files for the
SPIR-V Registry.  This includes:

* Header files for various languages.
* JSON files describing the grammar for the SPIR-V core instruction
  set and the extended instruction sets.
* The XML registry file.
* A tool to build the headers from the JSON grammar.