[turbofan] Add support for (deferred) instance migration.

src/compiler/simplified-operator.h

 // 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.
 
 #ifndef V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 #define V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 
 #include <iosfwd>
 
 #include "src/base/compiler-specific.h"
@@ skipping 127 matching lines @@
   kCheckForMinusZero,
   kDontCheckForMinusZero,
 };
 
 size_t hash_value(CheckForMinusZeroMode);
 
 std::ostream& operator<<(std::ostream&, CheckForMinusZeroMode);
 
 CheckForMinusZeroMode CheckMinusZeroModeOf(const Operator*) WARN_UNUSED_RESULT;
 
+// Flags for map checks.
+enum class CheckMapsFlag : uint8_t {
+  kNone = 0u,
+  kTryMigrateInstance = 1u << 0,  // Try instance migration.
+};
+typedef base::Flags<CheckMapsFlag> CheckMapsFlags;
+
+DEFINE_OPERATORS_FOR_FLAGS(CheckMapsFlags)
+
+std::ostream& operator<<(std::ostream&, CheckMapsFlags);
+
 // A descriptor for map checks.
 class CheckMapsParameters final {
  public:
-  explicit CheckMapsParameters(ZoneHandleSet<Map> const& maps) : maps_(maps) {}
+  CheckMapsParameters(CheckMapsFlags flags, ZoneHandleSet<Map> const& maps)
+      : flags_(flags), maps_(maps) {}
 
+  CheckMapsFlags flags() const { return flags_; }
   ZoneHandleSet<Map> const& maps() const { return maps_; }
 
  private:
+  CheckMapsFlags const flags_;
   ZoneHandleSet<Map> const maps_;
 };
 
 bool operator==(CheckMapsParameters const&, CheckMapsParameters const&);
 bool operator!=(CheckMapsParameters const&, CheckMapsParameters const&);
 
 size_t hash_value(CheckMapsParameters const&);
 
 std::ostream& operator<<(std::ostream&, CheckMapsParameters const&);
 
@@ skipping 191 matching lines @@
   const Operator* ChangeFloat64ToTagged();
   const Operator* ChangeFloat64ToTaggedPointer();
   const Operator* ChangeTaggedToBit();
   const Operator* ChangeBitToTagged();
   const Operator* TruncateTaggedToWord32();
   const Operator* TruncateTaggedToFloat64();
   const Operator* TruncateTaggedToBit();
 
   const Operator* CheckIf();
   const Operator* CheckBounds();
-  const Operator* CheckMaps(ZoneHandleSet<Map>);
+  const Operator* CheckMaps(CheckMapsFlags, ZoneHandleSet<Map>);
 
   const Operator* CheckHeapObject();
   const Operator* CheckInternalizedString();
   const Operator* CheckNumber();
   const Operator* CheckSmi();
   const Operator* CheckString();
 
   const Operator* CheckedInt32Add();
   const Operator* CheckedInt32Sub();
   const Operator* CheckedInt32Div();
@@ skipping 71 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(SimplifiedOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SIMPLIFIED_OPERATOR_H_