Debugger: use debug break slots to break at function exit.

src/heap/objects-visiting-inl.h

Index: src/heap/objects-visiting-inl.h
diff --git a/src/heap/objects-visiting-inl.h b/src/heap/objects-visiting-inl.h
index 03baabb7b73c898df0d503fb79cf1100bd6b902c..e3e8e710203ea03bdb376d97a03d6ba6722326bb 100644
--- a/src/heap/objects-visiting-inl.h
+++ b/src/heap/objects-visiting-inl.h
@@ -233,11 +233,9 @@ void StaticMarkingVisitor<StaticVisitor>::VisitCell(Heap* heap,
 template <typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitDebugTarget(Heap* heap,
                                                            RelocInfo* rinfo) {
-  DCHECK((RelocInfo::IsJSReturn(rinfo->rmode()) &&
-          rinfo->IsPatchedReturnSequence()) ||
-         (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
-          rinfo->IsPatchedDebugBreakSlotSequence()));
-  Code* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
+  DCHECK(RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
+         rinfo->IsPatchedDebugBreakSlotSequence());
+  Code* target = Code::GetCodeFromTargetAddress(rinfo->debug_call_address());
   heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
   StaticVisitor::MarkObject(heap, target);
 }
@@ -788,7 +786,6 @@ void Code::CodeIterateBody(ObjectVisitor* v) {
                   RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) |
                   RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) |
                   RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED) |
-                  RelocInfo::ModeMask(RelocInfo::JS_RETURN) |
                   RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) |
                   RelocInfo::kDebugBreakSlotMask;
 
@@ -816,7 +813,6 @@ void Code::CodeIterateBody(Heap* heap) {
                   RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) |
                   RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) |
                   RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED) |
-                  RelocInfo::ModeMask(RelocInfo::JS_RETURN) |
                   RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) |
                   RelocInfo::kDebugBreakSlotMask;