[clang] [mlir] [OpenACC][NFCI] Implement 'helpers' for all of the clauses I've used so far (PR #137396)

[Andy Kaylor via cfe-commits]

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@@ -1785,6 +1850,21 @@ def OpenACC_DataOp : OpenACC_Op<"data",
     /// Return the wait devnum value clause for the given device_type if
     /// present.
     mlir::Value getWaitDevnum(mlir::acc::DeviceType deviceType);
+    /// Add an entry to the 'async-only' attribute (clause spelled without
+    /// arguments)for each of the additional device types (or a none if it is
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andykaylor wrote:

```suggestion
    /// arguments) for each of the additional device types (or a none if it is
```

https://github.com/llvm/llvm-project/pull/137396