[llvm] [TargetLowering][COFF] Allow GlobalAlias in lowerRelativeReference (PR #220674)

[Eli Friedman via llvm-commits]

https://github.com/efriedma-quic commented:

I'd like to see a negative test checking that we reject the forms of aliases that we're not intending to accept.

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We should reject the cases that would require a 64-bit relocation, instead of generating wrong code.  But it's not really relevant to this patch; I'm okay with just opening an issue to follow up.

https://github.com/llvm/llvm-project/pull/220674