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

[Owen Anderson via llvm-commits]

resistor wrote:

> @resistor The test `llvm/test/TableGen/CPtrWildcard.td` fails on `powerpc64le-*-linux` and `powerpc64-ibm-aix`. It generates:
> 
> ```
> "/* 8*/ OPC_CheckChild1Type, /*MVT::c64*/1|128,2/*257*/," instead of
> "/* 8*/ OPC_CheckChild1Type, /*MVT::c64*/126|128,1/*254*/,"
> 
> "/*    18*/ OPC_CheckChild1Type, /*MVT::c128*/2|128,2/*258*/," instead of
> "/*    18*/ OPC_CheckChild1Type, /*MVT::c128*/127|128,1/*255*/,"
> ```
> 
> Should those numbers be different on different platforms? Or is there something that can be tolerable?

I would expect those to be stable across platforms, so the difference is surprising to me.

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