[SPIRV] Symbolic operands constants aren’t entirely accurate.

[winocm]

Unlike MLIR, the LLVM SPIR-V target relies on a manually maintained list of symbolic operand enumerations. This has resulted in various issues such as ‘UnsignedInt32’ not being spelled correctly or various capabilities not having their related extensions, or related operands not having their related capabilities added.

It would be nice if we could adapt the SPIR-V scripts from MLIR to automatically generate prefixed enumerations and such from the official SPIR-V registry. This way there won’t be any confusion or discrepancy between various symbolic operands.