[llvm] [SimplifyCFG][Attributes] Preserve some non-equal attrs when intersecting (PR #111014)

[Nikita Popov via llvm-commits]

nikic wrote:

> Any thoughts on adding memoryeffects to params?

MemoryEffects is the combination of Location + ModRef. For arguments, specifying the location is always "argmem", so we only need to specify the ModRef information, which is encoded by readonly/writeonly. So I don't think using MemoryEffects on arguments would make sense.

https://github.com/llvm/llvm-project/pull/111014