[clang] [OpenACC] Implement Default clause for Compute Constructs (PR #88135)

[Alexey Bataev via cfe-commits]

================
@@ -51,6 +51,36 @@ class OpenACCClauseWithParams : public OpenACCClause {
   SourceLocation getLParenLoc() const { return LParenLoc; }
 };
 
+// A 'default' clause, has the optional 'none' or 'present' argument.
----------------
alexey-bataev wrote:

```suggestion
/// A 'default' clause, has the optional 'none' or 'present' argument.
```


https://github.com/llvm/llvm-project/pull/88135