RFR (S) 8249140: fail to build hotspot with gcc-4.8.5

[linzang(臧琳)]

Hi
                May I ask your help to review the fix of 8249140, which cause hotspot build fail with gcc-4.8.5
              Bug: https://bugs.openjdk.java.net/browse/JDK-8249140
                Webrev: http://cr.openjdk.java.net/~lzang/8249140/webrev/
                Thanks!

BRs,
Lin