Move stack unwinding logic into the runtime.

src/frames-inl.h

Index: src/frames-inl.h
diff --git a/src/frames-inl.h b/src/frames-inl.h
index 824c1a762046f7f24fbdfbb1c9b7150542732764..815bb5617754028f3685417c665de362c2864e72 100644
--- a/src/frames-inl.h
+++ b/src/frames-inl.h
@@ -77,6 +77,18 @@ inline bool StackHandler::is_finally() const {
 }
 
 
+inline Context* StackHandler::context() const {
+  const int offset = StackHandlerConstants::kContextOffset;
+  return Context::cast(Memory::Object_at(address() + offset));
+}
+
+
+inline Code* StackHandler::code() const {
+  const int offset = StackHandlerConstants::kCodeOffset;
+  return Code::cast(Memory::Object_at(address() + offset));
+}
+
+
 inline StackHandler::Kind StackHandler::kind() const {
   const int offset = StackHandlerConstants::kStateIntOffset;
   return KindField::decode(Memory::unsigned_at(address() + offset));
@@ -89,6 +101,12 @@ inline unsigned StackHandler::index() const {
 }
 
 
+inline Address StackHandler::frame_pointer() const {
+  const int offset = StackHandlerConstants::kFPOffset;
+  return Memory::Address_at(address() + offset);
+}
+
+
 inline Object** StackHandler::context_address() const {
   const int offset = StackHandlerConstants::kContextOffset;
   return reinterpret_cast<Object**>(address() + offset);