Dont do expensive dcheck in hot path

Summary:
recent change to cache TL element pointer in its ThreadEntrySet added more paths where debug
builds check the consistency of the set. The checks can become expensive.
Remove them from the checks done in get / reset paths.

Reviewed By: sarangbh, bikash-c

Differential Revision: D76601252

fbshipit-source-id: 5d1c875a276279ed302099267f7e55066e3fdbb3

Author: Nitin Garg

third-party/folly/src/folly/detail/ThreadLocalDetail.h

@@ -357,7 +357,6 @@ struct ThreadEntrySet {
   }
 
   int64_t getIndexFor(ThreadEntry* entry) const {
-    DCHECK(basicSanity());
     auto iter = entryToVectorSlot.find(entry);
     if (iter != entryToVectorSlot.end()) {
       return static_cast<int64_t>(iter->second);
@@ -371,7 +370,6 @@ struct ThreadEntrySet {
    * ElementWrapper array used for fast access from the thread itself.
    */
   void* getPtrForThread(ThreadEntry* entry) const {
-    DCHECK(basicSanity());
     auto index = getIndexFor(entry);
     if (index < 0) {
       return nullptr;