[scudo] Use nullptr instead of integer-to-pointer cast

compiler-rt/lib/scudo/standalone/combined.h

void storeDeallocationStackMaybe(Options Options, void *Ptr, u8 PrevTag,
     u32 DeallocationTid = getThreadID();
 
     storeRingBufferEntry(addFixedTag(untagPointer(Ptr), PrevTag),
                          AllocationTrace, AllocationTid, Size,
                          DeallocationTrace, DeallocationTid);
   }
 
   static const size_t NumErrorReports =
-      sizeof(((scudo_error_info *)0)->reports) /
-      sizeof(((scudo_error_info *)0)->reports[0]);
+      sizeof(((scudo_error_info *)nullptr)->reports) /
+      sizeof(((scudo_error_info *)nullptr)->reports[0]);
 
   static void getInlineErrorInfo(struct scudo_error_info *ErrorInfo,
                                  size_t &NextErrorReport, uintptr_t FaultAddr,
                                  const StackDepot *Depot,
                                  const char *RegionInfoPtr, const char *Memory,
                                  const char *MemoryTags, uintptr_t MemoryAddr,
                                  size_t MemorySize, size_t MinDistance,
                                  size_t MaxDistance) {