Replace IsSymbolInCommonBlock function

Author: mrkajetanp

flang/lib/Semantics/resolve-directives.cpp

@@ -2901,20 +2901,6 @@ void ResolveOmpTopLevelParts(
   });
 }
 
-static bool IsSymbolInCommonBlock(const Symbol &symbol) {
-  // TODO Improve the performance of this predicate function.
-  //      Going through all symbols sequentially, in all common blocks, can be
-  //      slow when there are many symbols. A possible optimization is to add
-  //      an OmpInCommonBlock flag to Symbol, to make it possible to quickly
-  //      test if a given symbol is in a common block.
-  for (const auto &cb : symbol.owner().commonBlocks()) {
-    if (IsCommonBlockContaining(cb.second.get(), symbol)) {
-      return true;
-    }
-  }
-  return false;
-}
-
 static bool IsSymbolThreadprivate(const Symbol &symbol) {
   if (const auto *details{symbol.detailsIf<HostAssocDetails>()}) {
     return details->symbol().test(Symbol::Flag::OmpThreadprivate);
@@ -2943,7 +2929,7 @@ static bool IsSymbolPrivate(const Symbol &symbol) {
     case Scope::Kind::BlockConstruct:
       return !symbol.attrs().test(Attr::SAVE) &&
           !symbol.attrs().test(Attr::PARAMETER) && !IsAssumedShape(symbol) &&
-          !IsSymbolInCommonBlock(symbol);
+          !symbol.flags().test(Symbol::Flag::InCommonBlock);
     default:
       return false;
     }