8336692: Redo fix for JDK-8284620

Reviewed-by: dlong

Author: Vladimir Kozlov

src/hotspot/share/asm/codeBuffer.cpp

@@ -135,10 +135,11 @@ CodeBuffer::~CodeBuffer() {
     // Previous incarnations of this buffer are held live, so that internal
     // addresses constructed before expansions will not be confused.
     cb->free_blob();
+  }
+  if (_overflow_arena != nullptr) {
     // free any overflow storage
-    delete cb->_overflow_arena;
+    delete _overflow_arena;
   }
-
   if (_shared_trampoline_requests != nullptr) {
     delete _shared_trampoline_requests;
   }
@@ -973,8 +974,6 @@ void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
     CodeSection* this_sect = code_section(n);
     this_sect->take_over_code_from(cb_sect);
   }
-  _overflow_arena = cb->_overflow_arena;
-  cb->_overflow_arena = nullptr;
   // Make sure the old cb won't try to use it or free it.
   DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
 }