[turbofan] Add Symbol feedback to Equal/StrictEqual.

src/compiler/verifier.cc

 // Copyright 2014 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/verifier.h"
 
 #include <algorithm>
 #include <deque>
 #include <queue>
 #include <sstream>
@@ skipping 1160 matching lines @@
       CheckValueInputIs(node, 0, Type::Any());
       CheckTypeIs(node, Type::Receiver());
       break;
     case IrOpcode::kCheckSmi:
       CheckValueInputIs(node, 0, Type::Any());
       break;
     case IrOpcode::kCheckString:
       CheckValueInputIs(node, 0, Type::Any());
       CheckTypeIs(node, Type::String());
       break;
+    case IrOpcode::kCheckSymbol:
+      CheckValueInputIs(node, 0, Type::Any());
+      CheckTypeIs(node, Type::Symbol());
+      break;
 
     case IrOpcode::kCheckedInt32Add:
     case IrOpcode::kCheckedInt32Sub:
     case IrOpcode::kCheckedInt32Div:
     case IrOpcode::kCheckedInt32Mod:
     case IrOpcode::kCheckedUint32Div:
     case IrOpcode::kCheckedUint32Mod:
     case IrOpcode::kCheckedInt32Mul:
     case IrOpcode::kCheckedInt32ToTaggedSigned:
     case IrOpcode::kCheckedUint32ToInt32:
@@ skipping 570 matching lines @@
          replacement->op()->EffectOutputCount() > 0);
   DCHECK(!NodeProperties::IsFrameStateEdge(edge) ||
          replacement->opcode() == IrOpcode::kFrameState);
 }
 
 #endif  // DEBUG
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8