[flang] Carry over the derived type from target in pointer remapping

[clementval]

Summary

When calling PointerAssociateRemapping the dynamic type information
from the target needs to be carried over to the pointer if any.

[clementval]

Ping

flang/runtime/pointer.cpp

if (j == 0) {
       byteStride *= dim.Extent();
     }
   }
   if (pointer.Elements() > target.Elements()) {
     terminator.Crash("PointerAssociateRemapping: too many elements in remapped "
                      "pointer (%zd > %zd)",
         pointer.Elements(), target.Elements());
   }
+  if (auto *pointerAddendum{pointer.Addendum()}) {
+    if (const auto *targetAddendum{target.Addendum()}) {
+      if (const auto *derived{targetAddendum->derivedType()}) {
+        pointerAddendum->set_derivedType(derived);
+      }
+    }
+  }
 }
 
 int RTNAME(PointerAllocate)(Descriptor &pointer, bool hasStat,
     const Descriptor *errMsg, const char *sourceFile, int sourceLine) {
   Terminator terminator{sourceFile, sourceLine};
   if (!pointer.IsPointer()) {
     return ReturnError(terminator, StatInvalidDescriptor, errMsg, hasStat);
   }