[llvm] [SandboxVectorizer] Define SeedBundle: a set of instructions to be vectorized [retry] (PR #111073)

[via llvm-commits]

Sterling-Augustine wrote:

The only comment not directly addressed is about the need for the typedef:

"The SeedList type is used for the internal vector but it's also used in the constructor, which I find a bit confusing.
Since it's used internally it should not be public, because this is exposing an implementation detail, but since it's also used in the constructor then it should be public?

If we make this private, would there be a real need to have a separate typedef for the type used in the constructor ? I don't think we would really need one."

My response:

The type is also returned as a MutableArrayReference by getSlice. So the question here would be three-fold:

How do we expect clients to iterate over slices?
Would they need to construct new SeedBundles out of a list of possible seeds? 
Is it more convenient to do either of the above with a type?

I'm not particularly attached, but once I find myself using the same type in multiple places, I like a name for it, personally.

https://github.com/llvm/llvm-project/pull/111073