[CIR][NFC] Fix warning in MemOrder lowering

[andykaylor]

This fixes a warning about having a default case in a fully covered enum switch statement.

[llvmbot]

@llvm/pr-subscribers-clangir

@llvm/pr-subscribers-clang

Author: Andy Kaylor (andykaylor)

Changes

This fixes a warning about having a default case in a fully covered enum switch statement.

---

Full diff: https://github.com/llvm/llvm-project/pull/154609.diff

1 Files Affected:

• (modified) clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp (+1-2)

diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index ed5d9b83fc60e..9972d7612105d 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -1181,9 +1181,8 @@ getLLVMMemOrder(std::optional<cir::MemOrder> memorder) {
     return mlir::LLVM::AtomicOrdering::acq_rel;
   case cir::MemOrder::SequentiallyConsistent:
     return mlir::LLVM::AtomicOrdering::seq_cst;
-  default:
-    llvm_unreachable("unknown memory order");
   }
+  llvm_unreachable("unknown memory order");
 }
 
 mlir::LogicalResult CIRToLLVMLoadOpLowering::matchAndRewrite(