[clang] [CIR] Add support for indirect calls (PR #139748)

[Bruno Cardoso Lopes via cfe-commits]

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@@ -1500,6 +1507,14 @@ static void prepareTypeConverter(mlir::LLVMTypeConverter &converter,
   converter.addConversion([&](cir::BF16Type type) -> mlir::Type {
     return mlir::BFloat16Type::get(type.getContext());
   });
+  converter.addConversion([&](cir::FuncType type) -> mlir::Type {
+    auto result = converter.convertType(type.getReturnType());
+    llvm::SmallVector<mlir::Type> arguments;
+    if (converter.convertTypes(type.getInputs(), arguments).failed())
+      llvm_unreachable("Failed to convert function type parameters");
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bcardosolopes wrote:

Too bad we can't emit an error here. Perhaps instead of saying failed use something like "cir::FuncType conversion NYI"?  

https://github.com/llvm/llvm-project/pull/139748