[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 guess 'core' is a good term. Even on that link, "core" and "contributed" dialects are mixed without designation of which is which, and I expect that will grow over time, but it's probably fine to say we're lowering to "core" dialects even if it's an arbitrary subset of what other people might think of as core dialects.

How about `-emit-core-mlir`?

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