[turbofan] Revive the VectorSlotPair and also put feedback on JSCallFunction.

src/handles.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/handles.h"
 
 namespace v8 {
 namespace internal {
 
-
 int HandleScope::NumberOfHandles(Isolate* isolate) {
   HandleScopeImplementer* impl = isolate->handle_scope_implementer();
   int n = impl->blocks()->length();
   if (n == 0) return 0;
   return ((n - 1) * kHandleBlockSize) + static_cast<int>(
       (isolate->handle_scope_data()->next - impl->blocks()->last()));
 }
 
 
 Object** HandleScope::Extend(Isolate* isolate) {
@@ skipping 99 matching lines @@
   data->next = prev_next_;
   data->limit = prev_limit_;
 #ifdef DEBUG
   handles_detached_ = true;
 #endif
   return deferred;
 }
 
 }  // namespace internal
 }  // namespace v8