[lld] [LLD][COFF] Fix handling of weak aliases referencing lazy symbols (PR #112243)

[Jacek Caban via llvm-commits]

cjacek wrote:

I encountered this issue while working with ARM64EC code, which makes heavy use of weak (anti-dependency) aliases. However, the problem also affects other targets. The test in this PR fails on an assertion during a cast in `getWeakAlias`.

https://github.com/llvm/llvm-project/pull/112243