[llvm] [GlobalOpt] Don't query TTI on a llvm.memcpy declaration. (PR #127760)

[Craig Topper via llvm-commits]

topperc wrote:

> Is it possible to write a regression test for this?

No target uses subtarget information in their implementation of `getNumBytesToPadGlobalArray` so I think the only thing we could test is the absence of the warning message from RISC-V.

https://github.com/llvm/llvm-project/pull/127760