8048192: (bf) Out of direct buffer memory message should include the limits

Reviewed-by: alanb, rriggs

src/java.base/share/classes/java/nio/Bits.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2019, 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
@@ -172,7 +172,10 @@ class Bits {                            // package-private
             }
 
             // no luck
-            throw new OutOfMemoryError("Direct buffer memory");
+            throw new OutOfMemoryError
+                ("Cannot reserve "
+                 + size + " bytes of direct buffer memory (allocated: "
+                 + RESERVED_MEMORY.get() + ", limit: " + MAX_MEMORY +")");
 
         } finally {
             if (interrupted) {