[llvm] [LTO] Turn ImportListsTy into a proper class (NFC) (PR #106427)

[Kazu Hirata via llvm-commits]

kazutakahirata wrote:

> > I'm happy to switch to lookup or find to preserve const, but I don't see how that fixes crashes. In LLVM, we build the import lists for different destination modules in a single thread and then we do actual imports in parallel. In Rust, do you do something a bit different like building import lists in parallel?
> 
> It's the same in Rust. It's just that previously the part doing the concurrent accesses was using read-only accesses, while it's now doing potential read-write accesses. From an API perspective this is definitely wrong.
> 
> Of course, it should only actually be an issue if one of the module identifiers is not part of ImportLists when doing the actual imports, so maybe something is wrong on the Rust side...

I see.  I guess it's still handy to have a read-only access to `ImportLits`.  I've posted https://github.com/llvm/llvm-project/pull/109036.  Please take a look.  Thanks!



https://github.com/llvm/llvm-project/pull/106427