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

darkbuck wants to merge 2 commits intollvm:mainllvm/llvm-project:mainfrom

darkbuck:hliao/main/intrin-ret-numdarkbuck/llvm-project:hliao/main/intrin-ret-numCopy head branch name to clipboard