8180020: Improve SymbolHashMap entry handling

Reviewed-by: coleenp, kevinw
Contributed-by: rachel.protacio@oracle.com

src/share/vm/oops/constantPool.hpp

 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -983,7 +983,7 @@ class SymbolHashMap: public CHeapObj<mtSymbol> {
         delete(cur);
       }
     }
-    delete _buckets;
+    FREE_C_HEAP_ARRAY(SymbolHashMapBucket, _buckets, mtSymbol);
   }
 }; // End SymbolHashMap class