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

src/mips/full-codegen-mips.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_MIPS
 
 // Note on Mips implementation:
 //
@@ skipping 1163 matching lines @@
   __ bind(&no_descriptors);
   __ Drop(1);
   __ jmp(&exit);
 
   // We got a fixed array in register v0. Iterate through that.
   Label non_proxy;
   __ bind(&fixed_array);
 
   __ li(a1, FeedbackVector());
   __ li(a2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ sw(a2, FieldMemOperand(a1, FixedArray::OffsetOfElementAt(slot.ToInt())));
+  int vector_index = FeedbackVector()->GetIndex(slot);
+  __ sw(a2, FieldMemOperand(a1, FixedArray::OffsetOfElementAt(vector_index)));
 
   __ li(a1, Operand(Smi::FromInt(1)));  // Smi indicates slow check
   __ lw(a2, MemOperand(sp, 0 * kPointerSize));  // Get enumerated object
   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   __ GetObjectType(a2, a3, a3);
   __ Branch(&non_proxy, gt, a3, Operand(LAST_JS_PROXY_TYPE));
   __ li(a1, Operand(Smi::FromInt(0)));  // Zero indicates proxy
   __ bind(&non_proxy);
   __ Push(a1, v0);  // Smi and array
   __ lw(a1, FieldMemOperand(v0, FixedArray::kLengthOffset));
@@ skipping 4005 matching lines @@
       Assembler::target_address_at(pc_immediate_load_address)) ==
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS