[clang] [llvm] [llvm] Support llvm::Any across shared libraries on windows (PR #108051)

[Thomas Fransham via cfe-commits]

fsfod wrote:

> What are the implications/requirements for users of DataflowAnalysis? Every instance specifices it's own lattice, which is converted to/from llvm::Any. Will every lattice definition require these new declarations?

If you think they will be used from external from the llvm library including by tests then yes. 
I wish i could just put the visibility attribute on the Any Id field its self, but windows uses two different attributes to import and export a symbol which causes issues when its used by different codebases that require it to be in a different state.

https://github.com/llvm/llvm-project/pull/108051