8335801: [11u] Backport of 8210988 to 11u removes gcc warnings

[gnu-andrew]

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) and -xc99=%none (reverting 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)

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Progress

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• [ ] JDK-8335801 needs maintainer approval

Issue

• JDK-8335801: [11u] Backport of 8210988 to 11u removes gcc warnings (Bug - P4 - Requested)

Reviewers

• Paul Hohensee (@phohensee - Reviewer)

Reviewing

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