[clang] [CIR] Initial implementation of lowering CIR to MLIR (PR #127835)

[Andy Kaylor via cfe-commits]

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@@ -2958,6 +2958,8 @@ defm clangir : BoolFOption<"clangir",
   BothFlags<[], [ClangOption, CC1Option], "">>;
 def emit_cir : Flag<["-"], "emit-cir">, Visibility<[ClangOption, CC1Option]>,
   Group<Action_Group>, HelpText<"Build ASTs and then lower to ClangIR">;
+def emit_cir_mlir : Flag<["-"], "emit-cir-mlir">, Visibility<[CC1Option]>, Group<Action_Group>,
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andykaylor wrote:

I think "standard" dialects is somewhat contradictory to the MLIR philosophy, though in the abstract such a set seems to exist. There's just no good way to define it as far as I can see. I want to say this lowering would be to language-independent dialects, but I'm not sure where that leaves something like the OpenACC dialect.

https://github.com/llvm/llvm-project/pull/127835