[clang] [llvm] [BPF] Fix linking issues in static map initializers (PR #91310)

[Eli Friedman via llvm-commits]

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

Is it possible you could put this code into CompleteExternalDeclaration(), instead of writing it out in every place that can refer to the address of a function?

https://github.com/llvm/llvm-project/pull/91310