[clang] [CIR] Call code gen; create empty cir.func op (PR #113483)

[Aaron Ballman via cfe-commits]

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@@ -24,9 +27,140 @@ CIRGenModule::CIRGenModule(mlir::MLIRContext &context,
                            clang::ASTContext &astctx,
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AaronBallman wrote:

Yeah, this was part of https://github.com/llvm/llvm-project/pull/86080#discussion_r1535454524 and is actually starting to make me rethink the decision because the topic comes up on all of the CIR patches. MLIR thought there was a new policy for variable naming but that policy was never actually adopted by the wider community. CIR adopting MLIR's mistake is unfortunate. (I'm not insisting on changes -- we can do a mass rename in the future once CIR is basically done with upstreaming, unless MLIR is successful at getting their proposed policy change adopted by the wider community.)

https://github.com/llvm/llvm-project/pull/113483