[llvm] [offload] add handling of memory alignment to MemoryManagerTy (PR #218418)

[Jan Trusiłło via llvm-commits]

================
@@ -218,6 +222,19 @@ class MemoryManagerTy {
     return TgtPtr;
   }
 
+  void changeKeyPtr(void *FinalPtr, NodeTy *NodePtr) {
+    std::lock_guard<std::mutex> LG(MapTableLock);
+    auto NodeHandle = PtrToNodeTable.extract(NodePtr->Ptr);
+    NodeHandle.mapped().Ptr = FinalPtr;
+    NodeHandle.key() = FinalPtr;
+    PtrToNodeTable.insert(std::move(NodeHandle));
+  }
+
+  void *alignPointer(void *PtrToBeAligned, size_t Alignment) {
----------------
311Volt wrote:

`"llvm/Support/Alignment.h"` is already included, so this can be written as:

```
void *alignPointer(void *Ptr, size_t Alignment) {
  return reinterpret_cast<void *>(alignAddr(Ptr, Align(Alignment)));
}
```

which behaves the same, except you also get `assert()`s against address overflow and non-power-of-two alignments

https://github.com/llvm/llvm-project/pull/218418