[clang] [CIR] Add undef handling to enable global lambdas (PR #169721)

[Erich Keane via cfe-commits]

================
@@ -240,7 +240,7 @@ class CIRAttrToValue {
         .Case<cir::IntAttr, cir::FPAttr, cir::ConstComplexAttr,
----------------
erichkeane wrote:

Its a Little weird to me that this is a hand-typed list here, and that we don't have some sort of tablegen to get this list?  Perhaps a task for a future patch :) 

https://github.com/llvm/llvm-project/pull/169721