[llvm] [llvm] replace static_assert with std::enable_if_t in ilist_node_impl (PR #127722)

[Saleem Abdulrasool via llvm-commits]

compnerd wrote:

> I think we should wait on https://github.com/llvm/llvm-project/pull/127850#issuecomment-2675535706 given that the code works fine in all the configurations supported at the moment.

I'm not sure I see the reason for that. This is correcting a rather subtle design point in the code which has nothing to do other windows support. Can you help me understand why this is something that we should hold up?

https://github.com/llvm/llvm-project/pull/127722