Add local flow step for parenthesized expressions

ql/src/codeql_ruby/controlflow/CfgNodes.qll

@@ -249,6 +249,11 @@ module ExprNodes {
     final ExprCfgNode getExpr(int n) { e.hasCfgChild(e.getExpr(n), this, result) }
   }
 
+  /** A control-flow node that wraps an `ExprSequence` AST expression. */
+  class ParenthesizedExprCfgNode extends ExprSequenceCfgNode {
+    ParenthesizedExprCfgNode() { this.getExpr() instanceof ParenthesizedExpr }
+  }
+
   /** A control-flow node that wraps a `VariableReadAccess` AST expression. */
   class VariableReadAccessCfgNode extends ExprCfgNode {
     override VariableReadAccess e;

ql/src/codeql_ruby/dataflow/internal/DataFlowPrivate.qll

@@ -124,6 +124,9 @@ private module Cached {
     exists(Ssa::Definition def | LocalFlow::localSsaFlowStep(def, nodeFrom, nodeTo))
     or
     nodeFrom.asExpr() = nodeTo.asExpr().(CfgNodes::ExprNodes::AssignExprCfgNode).getRhs()
+    or
+    nodeFrom.asExpr() =
+      nodeTo.asExpr().(CfgNodes::ExprNodes::ParenthesizedExprCfgNode).getLastExpr()
   }
 
   cached