[mlir][OpenMP][NFC] Fix gcc 14 warning

[tblah]

GCC couldn't tell that the enum is checked exhaustively and so was warning about there being no return on this path from the function.

[llvmbot]

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Author: Tom Eccles (tblah)

Changes

GCC couldn't tell that the enum is checked exhaustively and so was warning about there being no return on this path from the function.

---

Full diff: https://github.com/llvm/llvm-project/pull/151941.diff

1 Files Affected:

• (modified) mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp (+1)

diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 49e1e55c686a6..762cc88d9fc3d 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -3391,6 +3391,7 @@ static llvm::omp::Directive convertCancellationConstructType(
   case omp::ClauseCancellationConstructType::Taskgroup:
     return llvm::omp::Directive::OMPD_taskgroup;
   }
+  llvm_unreachable("Unhandled cancellation construct type");
 }
 
 static LogicalResult