Fixing the logic issue in TransformTypos::TransformDesignatedInitExpr #126113

-Transforming Indices: For array designators, transform the index expression
and update ExprChanged if it's modified.
-Correct Initializer Check: Compare the transformed initializer against the
original to accurately track changes.
-Single Initializer Transformation: The initializer is processed once, not
per designator, as each DesignatedInitExpr has one initializer.

Fixes #126113

Author: GS-GOAT

clang/lib/Sema/TreeTransform.h

@@ -13665,15 +13665,15 @@ TreeTransform<Derived>::TransformDesignatedInitExpr(DesignatedInitExpr *E) {
     }
 
     if (D.isArrayDesignator()) {
-      ExprResult Index = getDerived().TransformExpr(E->getArrayIndex(D));
-      if (Index.isInvalid())
+      ExprResult NewIndex = getDerived().TransformExpr(E->getArrayIndex(D));
+      if (NewIndex.isInvalid())
         return ExprError();
 
-      Desig.AddDesignator(
-          Designator::CreateArrayDesignator(Index.get(), D.getLBracketLoc()));
+      Desig.AddDesignator(Designator::CreateArrayDesignator(
+          NewIndex.get(), D.getLBracketLoc()));
 
-      ExprChanged = ExprChanged || Init.get() != E->getArrayIndex(D);
-      ArrayExprs.push_back(Index.get());
+      ExprChanged = ExprChanged || NewIndex.get() != E->getArrayIndex(D);
+      ArrayExprs.push_back(NewIndex.get());
       continue;
     }