Avoid calling SizeClassMap::MaxCachedHint on hot path, it's not free.

[alekseyshl]

Summary

Remove unecessary SizeClassMap::MaxCachedHint call.

[eugenis]

LGTM

compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator_local_cache.h

for (uptr i = 0; i < kNumClasses; i++) {
       PerClass *c = &per_class_[i];
       c->max_count = 2 * SizeClassMap::MaxCachedHint(i);
     }
   }
 
   NOINLINE void Refill(PerClass *c, SizeClassAllocator *allocator,
                        uptr class_id) {
     InitCache();
-    uptr num_requested_chunks = SizeClassMap::MaxCachedHint(class_id);
+    uptr num_requested_chunks = c->max_count / 2;
     allocator->GetFromAllocator(&stats_, class_id, c->chunks,
                                 num_requested_chunks);
     c->count = num_requested_chunks;
   }
 
   NOINLINE void Drain(PerClass *c, SizeClassAllocator *allocator, uptr class_id,
                       uptr count) {
     InitCache();