RFR: 8302368: [ZGC] Client build fails after JDK-8300255 [v2]

[Jie Fu]

> Hi all,
> 
> Please review this small change to fix the client vm build failure.
> 
> "__" redefined [-Werror] occurred if build without C2.
> 
> Thanks.
> Best regards,
> Jie

Jie Fu has updated the pull request incrementally with one additional commit since the last revision:

  Address review comment

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/12547/files
  - new: https://git.openjdk.org/jdk/pull/12547/files/b223f2c5..d25035c4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12547&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12547&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/12547.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12547/head:pull/12547

PR: https://git.openjdk.org/jdk/pull/12547