[clang] [CIR] Add atomic exchange operation (PR #158089)

[Bruno Cardoso Lopes via cfe-commits]

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@@ -4033,6 +4033,47 @@ def CIR_ThrowOp : CIR_Op<"throw"> {
 // Atomic operations
 //===----------------------------------------------------------------------===//
 
+def CIR_AtomicXchg : CIR_Op<"atomic.xchg", [
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bcardosolopes wrote:

Please add CIR to CIR tests for parsing/printing

https://github.com/llvm/llvm-project/pull/158089