[NFC] Rename load_from/store_to_memref to load_from/store_to_buffer

[Max191]

Renames iree_codegen.load_from_memref to iree_codegen.load_from_buffer, and iree_codegen.store_to_memref to iree_codegen.store_to_buffer for consistency with the op definition.

[qedawkins]

Why not just update the op description? memref is very clear to me.

[Max191]

Why not just update the op description? memref is very clear to me.

This is more consistent with recent changes upstream: llvm/llvm-project@8f91b10

[hanhanW]

I may make a bad suggestion in the previous review because I did not fully follow the upstream RFC: #20874 (review) I threw out the question because I recently saw the change.

I don't have a strong opinion about if it should be memref or buffer. People can have their custom buffer type system that does not use memref, and I think it is the idea of the upstream change. We might not have a real use case, so it may be an over-design idea. I think I'm more like looking for consistency, so I had the second comment about it: #20874 (comment)

It can be either memref or buffer, and I'll let you make the call.

[Max191]

I like the consistency with upstream, so I will make the change from memref to buffer.