Small cleanup refactoring of sp-to-fp offset and slot conversions

src/compiler/frame.h

Index: src/compiler/frame.h
diff --git a/src/compiler/frame.h b/src/compiler/frame.h
index 4c4c2409b46271e9ce9e605c862c77942487a3c9..4eae7b1a6558f12484ad6ac21308e4ee3b191b01 100644
--- a/src/compiler/frame.h
+++ b/src/compiler/frame.h
@@ -225,6 +225,11 @@ class FrameAccessState : public ZoneObject {
   void SetFrameAccessToFP() { access_frame_with_fp_ = true; }
   void SetFrameAccessToSP() { access_frame_with_fp_ = false; }
 
+  int GetSpToFpSlotCount() const {
+    return frame_->GetSpToFpSlotCount() + sp_delta();
+  }
+  int GetSpToFpOffset() const { return GetSpToFpSlotCount() * kPointerSize; }
+
   // Get the frame offset for a given spill slot. The location depends on the
   // calling convention and the specific frame layout, and may thus be
   // architecture-specific. Negative spill slots indicate arguments on the