hg: jdk/sandbox: 8249875: GCC 10 warnings -Wtype-limits with JFR code

[chris.hegarty at oracle.com]

Changeset: 942b669a4ae3
Author:    ysuenaga
Date:      2020-07-23 12:19 +0900
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/942b669a4ae3

8249875: GCC 10 warnings -Wtype-limits with JFR code
Reviewed-by: mgronlun

! src/hotspot/share/jfr/utilities/jfrDoublyLinkedList.hpp
! src/hotspot/share/jfr/utilities/jfrHashtable.hpp