[flang][runtime] Temporary fix for unresolved reference in CUDA F18 runtime. (#85294)

Avoid referencing executionEnvironment in the device code, since
environment.cpp is not part of the CUDA build yet.
This is a temporary fix before #85182 is merged.

Author: vzakhari

flang/runtime/pointer.cpp

@@ -185,6 +185,7 @@ int RTDEF(PointerDeallocate)(Descriptor &pointer, bool hasStat,
   if (!pointer.IsAllocated()) {
     return ReturnError(terminator, StatBaseNull, errMsg, hasStat);
   }
+#if !defined(RT_DEVICE_COMPILATION)
   if (executionEnvironment.checkPointerDeallocation) {
     // Validate the footer.  This should fail if the pointer doesn't
     // span the entire object, or the object was not allocated as a
@@ -200,6 +201,7 @@ int RTDEF(PointerDeallocate)(Descriptor &pointer, bool hasStat,
           terminator, StatBadPointerDeallocation, errMsg, hasStat);
     }
   }
+#endif
   return ReturnError(terminator,
       pointer.Destroy(/*finalize=*/true, /*destroyPointers=*/true, &terminator),
       errMsg, hasStat);