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

[Jessica Clarke via llvm-commits]

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@@ -367,6 +367,9 @@ def aarch64mfp8 : ValueType<8,  253>;  // 8-bit value in FPR (AArch64)
 def c64 : VTCheriCapability<64, 254>;   // 64-bit CHERI capability value
 def c128 : VTCheriCapability<128, 255>; // 128-bit CHERI capability value
 
+// Pseudo valuetype mapped to the current CHERI capability pointer size.
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jrtc27 wrote:

`iPTR` has gained `// Should only be used in TableGen.` since I added cPTR in its current form; please add that comment here too

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