[llvm] [TableGen, CodeGen, CHERI] Add support for the cPTR wildcard value type. (PR #158426)

[Alexander Richardson via llvm-commits]

arichardson wrote:

I don't understand enough about the tablegen internals to review this properly so I'll leave it to @jrtc27 and others.

https://github.com/llvm/llvm-project/pull/158426