[llvm] [CostModel] Estimate the codesize cost of switch (PR #163569)

[Nikita Popov via llvm-commits]

nikic wrote:

> > Why did you change this from the implementation that queries the load etc costs to one that doesn't?
> 
> Because it's more complicated to query these costs in TTIImpl, and I expected the code size cost of most targets to be consistent, I tried to simplify this code. Will change it back to the general form with queries if that's better.

I think you're right that for codesize it probably does not make sense to query (unless maybe there are differences across backends, like some measure code size in bytes while others in instructions?)

https://github.com/llvm/llvm-project/pull/163569