[clang] [llvm] [WebAssembly] support getVT from `externref` and `funcref` (PR #97080)

[Heejin Ahn via cfe-commits]

https://github.com/aheejin commented:

What happens if you compile a file that really vectorizes reference types? The attached test doesn't seem to actually end up getting vectorized after all. Can you add a test that get vectorized?

https://github.com/llvm/llvm-project/pull/97080