[flang][OpenMP] Use parser::UnwrapRef instead of thing/value, NFC (llvm#164087)

Author: kparzysz

flang/lib/Semantics/check-omp-atomic.cpp

@@ -286,7 +286,7 @@ static std::optional<AnalyzedCondStmt> AnalyzeConditionalStmt(
   // Extract the evaluate::Expr from ScalarLogicalExpr.
   auto getFromLogical{[](const parser::ScalarLogicalExpr &logical) {
     // ScalarLogicalExpr is Scalar<Logical<common::Indirection<Expr>>>
-    const parser::Expr &expr{logical.thing.thing.value()};
+    auto &expr{parser::UnwrapRef<parser::Expr>(logical)};
     return GetEvaluateExpr(expr);
   }};
 

flang/lib/Semantics/resolve-directives.cpp

@@ -560,7 +560,7 @@ class OmpAttributeVisitor : DirectiveAttributeVisitor<llvm::omp::Directive> {
     auto getArgument{[&](auto &&maybeClause) {
       if (maybeClause) {
         // Scalar<Logical<Constant<common::Indirection<Expr>>>>
-        auto &parserExpr{maybeClause->v.thing.thing.thing.value()};
+        auto &parserExpr{parser::UnwrapRef<parser::Expr>(*maybeClause)};
         evaluate::ExpressionAnalyzer ea{context_};
         if (auto &&maybeExpr{ea.Analyze(parserExpr)}) {
           if (auto v{omp::GetLogicalValue(*maybeExpr)}) {