[llvm] [Intrinsic] Unify IIT_STRUCT{2-9} into ITT_STRUCT to support upto 257 return value (PR #160434)

[Rahul Joshi via llvm-commits]

jurahul wrote:

Suggested PR description:

Currently, Intrinsic can only have up to 9 return values. In case new intrinsics require more than 9 return values, additional
ITT_STRUCTxxx values need to be added to support > 9 return values.  Instead, this patch unifies them into a single IIT_STRUCT followed by a BYTE specifying the minimal 2 (encoded as 0) and maximal 257 (encoded as 255) return values.

https://github.com/llvm/llvm-project/pull/160434