[turbofan] Add Symbol feedback to Equal/StrictEqual.

src/compiler/js-type-hint-lowering.cc

 // Copyright 2017 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/compiler/js-type-hint-lowering.h"
 
 #include "src/compiler/js-graph.h"
 #include "src/compiler/operator-properties.h"
 #include "src/compiler/simplified-operator.h"
 #include "src/feedback-vector.h"
@@ skipping 64 matching lines @@
         return true;
       case CompareOperationHint::kNumber:
         *hint = NumberOperationHint::kNumber;
         return true;
       case CompareOperationHint::kNumberOrOddball:
         *hint = NumberOperationHint::kNumberOrOddball;
         return true;
       case CompareOperationHint::kAny:
       case CompareOperationHint::kNone:
       case CompareOperationHint::kString:
+      case CompareOperationHint::kSymbol:
       case CompareOperationHint::kReceiver:
       case CompareOperationHint::kInternalizedString:
         break;
     }
     return false;
   }
 
   const Operator* SpeculativeNumberOp(NumberOperationHint hint) {
     switch (op_->opcode()) {
       case IrOpcode::kJSAdd:
@@ skipping 226 matching lines @@
     Node* frame_state = NodeProperties::FindFrameStateBefore(deoptimize);
     deoptimize->ReplaceInput(0, frame_state);
     return deoptimize;
   }
   return nullptr;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8