[llvm] [Offload]: Skip copying of unused kernel-mapped data (PR #124723)

[Joseph Huber via llvm-commits]

================
@@ -386,6 +386,13 @@ struct LookupResult {
   LookupResult() : Flags({0, 0, 0}), TPR() {}
 
   TargetPointerResultTy TPR;
+
+  bool isEmpty() const {
+      bool IsEmpty = Flags.IsContained == 0
+              & Flags.ExtendsBefore == 0
+              & Flags.ExtendsAfter == 0;
+      return IsEmpty;
----------------
jhuber6 wrote:

```suggestion
  bool isEmpty() const {
      return !Flags.IsContained && !Flags.ExtendsBefore  && !Flags.ExtendsAfter;
```


https://github.com/llvm/llvm-project/pull/124723