[interpreter] source positions should not be emitted for dead code.

src/interpreter/source-position-table.h

 // Copyright 2016 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_INTERPRETER_SOURCE_POSITION_TABLE_H_
 #define V8_INTERPRETER_SOURCE_POSITION_TABLE_H_
 
 #include "src/assert-scope.h"
 #include "src/handles.h"
 #include "src/zone.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 
 class BytecodeArray;
 class FixedArray;
 class Isolate;
 
 namespace interpreter {
 
 class SourcePositionTableBuilder {
  public:
   explicit SourcePositionTableBuilder(Isolate* isolate, Zone* zone)
       : isolate_(isolate), entries_(zone) {}
 
-  void AddStatementPosition(int bytecode_offset, int source_position);
-  void AddExpressionPosition(int bytecode_offset, int source_position);
+  void AddStatementPosition(size_t bytecode_offset, int source_position);
+  void AddExpressionPosition(size_t bytecode_offset, int source_position);
+  void RevertPosition(size_t bytecode_offset);
   Handle<FixedArray> ToFixedArray();
 
  private:
   struct Entry {
     int bytecode_offset;
     uint32_t source_position_and_type;
   };
 
   void AssertMonotonic(int bytecode_offset) {
     DCHECK(entries_.size() == 0 ||
@@ skipping 34 matching lines @@
   int bytecode_offset_;
   int source_position_;
   DisallowHeapAllocation no_gc;
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_SOURCE_POSITION_TABLE_H_