RFR: 8321688: Build on linux with GCC 7.5.0 fails after 8319577 [v2]

[Guoxiong Li]

> Hi all,
> 
> This patch fixes the building failure introduced by [JDK-8319577](https://bugs.openjdk.org/browse/JDK-8319577) in old GCC version (linux & GCC 7.5.0 locally).
> 
> Thanks for the review.
> 
>  Best Regards,
> -- Guoxiong

Guoxiong Li has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Bump the needed version of GCC.
 - Revert previous change.
 - Merge branch 'master' into JDK-8321688
 - JDK-8321688

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17047/files
  - new: https://git.openjdk.org/jdk/pull/17047/files/46858210..f04bcd55

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17047&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17047&range=00-01

  Stats: 876 lines in 56 files changed: 520 ins; 166 del; 190 mod
  Patch: https://git.openjdk.org/jdk/pull/17047.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17047/head:pull/17047

PR: https://git.openjdk.org/jdk/pull/17047