6950617: Zero/Shark interface updates

Summary: Zero needs a couple of new methods to allow Shark to access the new frame anchor field.
Reviewed-by: twisti
Contributed-by: NGary Benson <gbenson@redhat.com>

src/cpu/zero/vm/frame_zero.cpp

@@ -36,6 +36,10 @@ bool frame::is_interpreted_frame() const {
   return zeroframe()->is_interpreter_frame();
 }
 
+bool frame::is_fake_stub_frame() const {
+  return zeroframe()->is_fake_stub_frame();
+}
+
 frame frame::sender_for_entry_frame(RegisterMap *map) const {
   assert(zeroframe()->is_entry_frame(), "wrong type of frame");
   assert(map != NULL, "map must be set");

src/cpu/zero/vm/frame_zero.hpp

@@ -61,6 +61,9 @@
     return zeroframe()->as_shark_frame();
   }
 
+ public:
+  bool is_fake_stub_frame() const;
+
  public:
   frame sender_for_nonentry_frame(RegisterMap* map) const;
 

src/cpu/zero/vm/javaFrameAnchor_zero.hpp

@@ -81,3 +81,7 @@
   ZeroFrame* last_Java_fp() const {
     return _last_Java_fp;
   }
+
+  static ByteSize last_Java_fp_offset() {
+    return byte_offset_of(JavaFrameAnchor, _last_Java_fp);
+  }

src/os_cpu/linux_zero/vm/thread_linux_zero.hpp

@@ -88,6 +88,12 @@
     return frame(last_Java_fp(), last_Java_sp());
   }
 
+ public:
+  static ByteSize last_Java_fp_offset() {
+    return byte_offset_of(JavaThread, _anchor) +
+      JavaFrameAnchor::last_Java_fp_offset();
+  }
+
  public:
   // Check for pending suspend requests and pending asynchronous
   // exceptions.  There are separate accessors for these, but