[wasm] Stack inspection support for asm.js frames

src/debug/debug-frames.cc

Index: src/debug/debug-frames.cc
diff --git a/src/debug/debug-frames.cc b/src/debug/debug-frames.cc
index c98f911f754275a42f0b92d3d226106369b71f79..5da1656fadd9977f2ff012e8e32fe3463895c3a9 100644
--- a/src/debug/debug-frames.cc
+++ b/src/debug/debug-frames.cc
@@ -77,23 +77,11 @@ Handle<Object> FrameInspector::GetExpression(int index) {
                        : handle(frame_->GetExpression(index), isolate_);
 }
 
-
 int FrameInspector::GetSourcePosition() {
-  if (is_optimized_) return deoptimized_frame_->GetSourcePosition();
-  AbstractCode* code;
-  int code_offset;
-  if (is_interpreted_) {
-    InterpretedFrame* frame = reinterpret_cast<InterpretedFrame*>(frame_);
-    code = AbstractCode::cast(frame->GetBytecodeArray());
-    code_offset = frame->GetBytecodeOffset();
-  } else {
-    code = AbstractCode::cast(frame_->LookupCode());
-    code_offset = static_cast<int>(frame_->pc() - code->instruction_start());
-  }
-  return code->SourcePosition(code_offset);
+  return is_optimized_ ? deoptimized_frame_->GetSourcePosition()
+                       : frame_->position();
 }
 
-
 bool FrameInspector::IsConstructor() {
   return is_optimized_ && !is_bottommost_
              ? deoptimized_frame_->HasConstructStub()