Merge pull request #22650 from owen-mc/go/undeprecate-parenexpr

Go: un-deprecate `ParenExpr`

Author: owen-mc

go/ql/lib/change-notes/2026-08-13-cfg.md

@@ -27,6 +27,3 @@ category: breaking
   - `EvalCompoundAssignRhsInstruction` now also represents increment and
     decrement operations, and it and `EvalImplicitInitInstruction` directly
     represent their associated writes.
-* `ParenExpr` has been deprecated because parenthesized expressions are no
-  longer extracted as separate AST nodes. The child expression now directly
-  takes the place of the parenthesized expression.

go/ql/lib/semmle/go/Expr.qll

@@ -544,11 +544,20 @@ class SliceLit extends ArrayOrSliceLit {
 }
 
 /**
- * DEPRECATED: `ParenExpr` is no longer extracted. Parenthesized expressions are
- * transparent in the AST; the child expression takes the place of the parenthesized
- * expression directly.
+ * A parenthesized expression.
+ *
+ * Examples:
+ *
+ * ```go
+ * (x + y)
+ * ```
+ *
+ * Note that `ParenExpr` is no longer extracted - the child expression takes
+ * the place of the parenthesized expression directly. This class only exists
+ * for compatibility with old databases, and will be deprecated and removed in
+ * the future.
  */
-deprecated class ParenExpr extends @parenexpr, Expr {
+class ParenExpr extends @parenexpr, Expr {
   /** Gets the expression between parentheses. */
   Expr getExpr() { result = this.getChildExpr(0) }