[jdk11u-dev] RFR: 8335801: [11u] Backport of 8210988 to 11u removes gcc warnings [v2]

[Andrew John Hughes]

> The backport of 8210988 contained a number of issues, the most serious of which is it completely removed warnings from `gcc` builds by changing `WARNING_CFLAGS_JDK` and `WARNING_CFLAGS_JVM`, but not defining `WARNINGS_ENABLE_ALL`, `WARNINGS_ENABLE_ADDITIONAL_JVM` and `DISABLED_WARNINGS`.
> 
> The other more minor issues are the silent inclusion of `-Wreorder` to clang builds (should be a backport of [JDK-8208672](https://bugs.openjdk.org/browse/JDK-8208672)) and `-xc99=%none` (reverting [JDK-8215296](https://bugs.openjdk.org/browse/JDK-8215296)), because new lines were used as is without comparing differences in what was being replaced.
> 
> All three of these changes show up clearly when comparing the 11u & 12u changesets, and are corrected by this patch.
> 
> I can also confirm this has the desired effect with warnings as my local build on GCC 13 now fails again, whereas it was passing before (we need some backports there to make that work)

Andrew John Hughes 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 three additional commits since the last revision:

 - Merge remote-tracking branch 'dev/master' into JDK-8335801
 - Merge remote-tracking branch 'dev/master' into JDK-8335801
 - 8335801: [11u] Backport of 8210988 to 11u removes gcc warnings

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

Changes:
  - all: https://git.openjdk.org/jdk11u-dev/pull/2838/files
  - new: https://git.openjdk.org/jdk11u-dev/pull/2838/files/b4fadd62..4e9ee141

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2838&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2838&range=00-01

  Stats: 34335 lines in 282 files changed: 19820 ins; 13189 del; 1326 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2838.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2838/head:pull/2838

PR: https://git.openjdk.org/jdk11u-dev/pull/2838