Revert of [compiler] Properly guard the speculative optimizations for instanceof.

src/full-codegen/full-codegen.h

 // 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.
 
 #ifndef V8_FULL_CODEGEN_FULL_CODEGEN_H_
 #define V8_FULL_CODEGEN_FULL_CODEGEN_H_
 
 #include "src/allocation.h"
 #include "src/assert-scope.h"
 #include "src/ast/ast.h"
@@ skipping 393 matching lines @@
 
   // Platform-specific code for equality comparison with a nil-like value.
   void EmitLiteralCompareNil(CompareOperation* expr,
                              Expression* sub_expr,
                              NilValue nil);
 
   // Bailout support.
   void PrepareForBailout(Expression* node, Deoptimizer::BailoutState state);
   void PrepareForBailoutForId(BailoutId id, Deoptimizer::BailoutState state);
 
-  // Returns the plain index for the FixedArray that backs the feedback vector.
-  int SlotToIndex(FeedbackVectorSlot slot) const {
-    return TypeFeedbackVector::GetIndexFromSpec(
-        literal()->feedback_vector_spec(), slot);
-  }
   // Returns a smi for the index into the FixedArray that backs the feedback
   // vector
   Smi* SmiFromSlot(FeedbackVectorSlot slot) const {
-    return Smi::FromInt(SlotToIndex(slot));
+    return Smi::FromInt(TypeFeedbackVector::GetIndexFromSpec(
+        literal()->feedback_vector_spec(), slot));
   }
 
   // Record a call's return site offset, used to rebuild the frame if the
   // called function was inlined at the site.
   void RecordJSReturnSite(Call* call);
 
   // Prepare for bailout before a test (or compare) and branch.  If
   // should_normalize, then the following comparison will not handle the
   // canonical JS true value so we will insert a (dead) test against true at
   // the actual bailout target from the optimized code. If not
@@ skipping 596 matching lines @@
   Address start_;
   Address instruction_start_;
   uint32_t length_;
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_FULL_CODEGEN_FULL_CODEGEN_H_