[clang] [clang][Interp] Integral pointers (PR #84159)

[Aaron Ballman via cfe-commits]

================
@@ -1505,12 +1509,17 @@ bool OffsetHelper(InterpState &S, CodePtr OpPC, const T &Offset,
     return true;
   }
 
-  if (!CheckNull(S, OpPC, Ptr, CSK_ArrayIndex))
-    return false;
+  if (!CheckNull(S, OpPC, Ptr, CSK_ArrayIndex)) {
+    // The CheckNul will have emitted a note already, but we only
+    // abort in C++, since this is fine in C.
+    if (S.getLangOpts().CPlusPlus)
+      return false;
+  }
 
   // Arrays of unknown bounds cannot have pointers into them.
-  if (!CheckArray(S, OpPC, Ptr))
+  if (!CheckArray(S, OpPC, Ptr)) {
     return false;
+  }
----------------
AaronBallman wrote:

```suggestion
  if (!CheckArray(S, OpPC, Ptr))
    return false;
```

https://github.com/llvm/llvm-project/pull/84159