[interpreter] Reduce size of OSR nesting level field.

src/objects.h

 // Copyright 2015 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_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 4552 matching lines @@
   void CopyBytecodesTo(BytecodeArray* to);
 
   // Layout description.
   static const int kConstantPoolOffset = FixedArrayBase::kHeaderSize;
   static const int kHandlerTableOffset = kConstantPoolOffset + kPointerSize;
   static const int kSourcePositionTableOffset =
       kHandlerTableOffset + kPointerSize;
   static const int kFrameSizeOffset = kSourcePositionTableOffset + kPointerSize;
   static const int kParameterSizeOffset = kFrameSizeOffset + kIntSize;
   static const int kInterruptBudgetOffset = kParameterSizeOffset + kIntSize;
-  // TODO(4764): The OSR nesting level is guaranteed to be in [0;6] bounds and
-  // could potentially be merged with another field (e.g. parameter_size).
   static const int kOSRNestingLevelOffset = kInterruptBudgetOffset + kIntSize;
-  static const int kHeaderSize = kOSRNestingLevelOffset + kIntSize;
+  static const int kHeaderSize = kOSRNestingLevelOffset + kCharSize;
 
   // Maximal memory consumption for a single BytecodeArray.
   static const int kMaxSize = 512 * MB;
   // Maximal length of a single BytecodeArray.
   static const int kMaxLength = kMaxSize - kHeaderSize;
 
   class BodyDescriptor;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArray);
@@ skipping 6434 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_