[scudo] Use fast get time in secondary.

[cferris]

Summary

When I moved the primary to use the faster get time syscall, I missed
the secondary use. Now fix the secondary to use this function too.

[Chia-hungDuan]

Just did a quick glance in the use of getMonotonicTime(). There is one place I think we may want to evaluate switching to getMonotonicTimeFast() too. Which is in tsd.h

inline bool tryLock() NO_THREAD_SAFETY_ANALYSIS {
  if (Mutex.tryLock()) {
    atomic_store_relaxed(&Precedence, 0);
    return true;
  }
  if (atomic_load_relaxed(&Precedence) == 0)
    atomic_store_relaxed(
        &Precedence,
        static_cast<uptr>(getMonotonicTime() >> FIRST_32_SECOND_64(16, 0)));
  return false;
}

https://github.com/llvm/llvm-project/blob/main/compiler-rt/lib/scudo/standalone/tsd.h#L46

(In timing.h, it may be also a candidate, but it's minor)

It's not necessary to be included in this change anyway, LGTM!

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

public:
 
   void store(Options Options, LargeBlock::Header *H) EXCLUDES(Mutex) {
     if (!canCache(H->CommitSize))
       return unmap(H);
 
     bool EntryCached = false;
     bool EmptyCache = false;
     const s32 Interval = atomic_load_relaxed(&ReleaseToOsIntervalMs);
-    const u64 Time = getMonotonicTime();
+    const u64 Time = getMonotonicTimeFast();
     const u32 MaxCount = atomic_load_relaxed(&MaxEntriesCount);
     CachedBlock Entry;
     Entry.CommitBase = H->CommitBase;
     Entry.CommitSize = H->CommitSize;
     Entry.BlockBegin = reinterpret_cast<uptr>(H + 1);
     Entry.MemMap = H->MemMap;
     Entry.Time = Time;
     if (useMemoryTagging<Config>(Options)) {