vector-based ICs did not update type feedback counts correctly.

src/x64/full-codegen-x64.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"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 1131 matching lines @@
   __ bind(&no_descriptors);
   __ addp(rsp, Immediate(kPointerSize));
   __ jmp(&exit);
 
   // We got a fixed array in register rax. Iterate through that.
   Label non_proxy;
   __ bind(&fixed_array);
 
   // No need for a write barrier, we are storing a Smi in the feedback vector.
   __ Move(rbx, FeedbackVector());
-  __ Move(FieldOperand(rbx, FixedArray::OffsetOfElementAt(slot.ToInt())),
+  int vector_index = FeedbackVector()->GetIndex(slot);
+  __ Move(FieldOperand(rbx, FixedArray::OffsetOfElementAt(vector_index)),
           TypeFeedbackVector::MegamorphicSentinel(isolate()));
   __ Move(rbx, Smi::FromInt(1));  // Smi indicates slow check
   __ movp(rcx, Operand(rsp, 0 * kPointerSize));  // Get enumerated object
   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   __ CmpObjectType(rcx, LAST_JS_PROXY_TYPE, rcx);
   __ j(above, &non_proxy);
   __ Move(rbx, Smi::FromInt(0));  // Zero indicates proxy
   __ bind(&non_proxy);
   __ Push(rbx);  // Smi
   __ Push(rax);  // Array
@@ skipping 3995 matching lines @@
   DCHECK_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64