[llvm] [LLVM][Verifier] Move intrinsic signature verification to declarations (PR #204478)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> After this change, we start failing on the external test suite: https://ci.swift.org/job/llvm.org/job/test-suite-verify-machineinstrs-x86_64-O3/job/main/774/. There, we have old .bc files which contain unused intrinsics with incorrect signatures, e.g., Bitcode/Regression/sap_fct_splitting/sap_fct_splitting.bc. (This would be the fully materialised case.)

It's unclear what exact intrinsics are causing this. Either way, if the signature is invalid, this probably should be handled by the AutoUpgrader.

https://github.com/llvm/llvm-project/pull/204478