Declare deleted new and delete operators in pairs in ScopeGuard

Summary: [Folly] Declare deleted `new` and `delete` operators in pairs in `ScopeGuard`.

Reviewed By: Orvid

Differential Revision: D10119848

fbshipit-source-id: 3588ed299248efd124d216bfaf5e472795f6a7aa

folly/ScopeGuard.h

@@ -230,6 +230,7 @@ class ScopeGuardForNewException {
   ScopeGuardForNewException(const ScopeGuardForNewException& other) = delete;
 
   void* operator new(std::size_t) = delete;
+  void operator delete(void*) = delete;
 
   FunctionType function_;
   int exceptionCounter_{uncaught_exceptions()};