[clang] [CIR] Upstream support for function/call calling conventions (PR #181170)

[Akimasa Watanuki via cfe-commits]

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@@ -2074,6 +2100,21 @@ ParseResult cir::FuncOp::parse(OpAsmParser &parser, OperationState &state) {
       return failure();
   }
 
+  auto callConvNameAttr = getCallingConvAttrName(state.name);
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Men-cotton wrote:

Change to `mlir::StringAttr`.

https://github.com/llvm/llvm-project/pull/181170