[clang][Sema] Fix a copy/paste bug in ~Sema()

[aaron.ballman]

LGTM! I have absolutely no idea how you would test the Sema destructor, so I think it's fine that this comes with no test coverage. Good catch!

clang/lib/Sema/Sema.cpp

Sema::~Sema() {
 
   // Detach from the external Sema source.
   if (ExternalSemaSource *ExternalSema
         = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
     ExternalSema->ForgetSema();
 
   // Delete cached satisfactions.
   std::vector<ConstraintSatisfaction *> Satisfactions;
-  Satisfactions.reserve(Satisfactions.size());
+  Satisfactions.reserve(SatisfactionCache.size());
   for (auto &Node : SatisfactionCache)
     Satisfactions.push_back(&Node);
   for (auto *Node : Satisfactions)
     delete Node;
 
   threadSafety::threadSafetyCleanup(ThreadSafetyDeclCache);
 
   // Destroys data sharing attributes stack for OpenMP