Use source position table in turbofan code.

src/debug/debug-frames.cc

 // 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.
 
 #include "src/debug/debug-frames.h"
 
 #include "src/frames-inl.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 50 matching lines @@
       frame_->function()->shared()->asm_function() &&
       !FLAG_turbo_asm_deoptimization) {
     return isolate_->factory()->undefined_value();
   }
   return is_optimized_ ? deoptimized_frame_->GetExpression(index)
                        : handle(frame_->GetExpression(index), isolate_);
 }
 
 
 int FrameInspector::GetSourcePosition() {
-  if (is_optimized_) {
-    return deoptimized_frame_->GetSourcePosition();
-  } else if (is_interpreted_) {
+  if (is_optimized_) return deoptimized_frame_->GetSourcePosition();
+  AbstractCode* code;
+  int code_offset;
+  if (is_interpreted_) {
     InterpretedFrame* frame = reinterpret_cast<InterpretedFrame*>(frame_);
-    BytecodeArray* bytecode_array = frame->GetBytecodeArray();
-    return bytecode_array->SourcePosition(frame->GetBytecodeOffset());
+    code = AbstractCode::cast(frame->GetBytecodeArray());
+    code_offset = frame->GetBytecodeOffset();
   } else {
-    Code* code = frame_->LookupCode();
-    int offset = static_cast<int>(frame_->pc() - code->instruction_start());
-    return code->SourcePosition(offset);
+    code = AbstractCode::cast(frame_->LookupCode());
+    code_offset = static_cast<int>(frame_->pc() - code->instruction_start());
   }
+  return code->SourcePosition(code_offset);
 }
 
 
 bool FrameInspector::IsConstructor() {
   return is_optimized_ && !is_bottommost_
              ? deoptimized_frame_->HasConstructStub()
              : frame_->IsConstructor();
 }
 
 Handle<Object> FrameInspector::GetContext() {
@@ skipping 129 matching lines @@
       if (!frames[i].function()->shared()->IsSubjectToDebugging()) continue;
       if (++count == index) return i;
     }
   }
   return -1;
 }
 
 
 }  // namespace internal
 }  // namespace v8