Cleanup std includes

Remove `deque` from files it isn't actually used in. Add it and `stack`
to files that it is - presumably they were previously transitively found
through other includes.

tools/SourceKit/lib/SwiftLang/CodeCompletionOrganizer.cpp

@@ -23,7 +23,6 @@
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/ilist.h"
 #include "llvm/ADT/ilist_node.h"
-#include <deque>
 
 using namespace SourceKit;
 using namespace CodeCompletion;