[heap] Remove some more dead code in MC

src/heap/mark-compact.h

Index: src/heap/mark-compact.h
diff --git a/src/heap/mark-compact.h b/src/heap/mark-compact.h
index 71584379346808f0ca624e86175d88828604d600..6e1a4ecf2e0695cd32baf9dec9cd71e8e3f9ad37 100644
--- a/src/heap/mark-compact.h
+++ b/src/heap/mark-compact.h
@@ -566,16 +566,6 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
 
   void AbortCompaction();
 
-  // Determine type of object and emit deletion log event.
-  static void ReportDeleteIfNeeded(HeapObject* obj, Isolate* isolate);
-
-  // Distinguishable invalid map encodings (for single word and multiple words)
-  // that indicate free regions.
-  static const uint32_t kSingleFreeEncoding = 0;
-  static const uint32_t kMultiFreeEncoding = 1;
-
-  inline Isolate* isolate() const;
-
   CodeFlusher* code_flusher() { return code_flusher_; }
   inline bool is_code_flushing_enabled() const { return code_flusher_ != NULL; }