RFR: 8375311: Some builds are missing debug helpers

[Martin Doerr]

On Wed, 14 Jan 2026 15:32:28 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> [JDK-8318834](https://bugs.openjdk.org/browse/JDK-8318834) pointed out that on linux s390x, debug builds were missing debug helpers .
> This happened because we enabled some time ago linktime gc (-Wl,--gc-sections in the linker flags, plus -ffunction-sections -fdata-sections in compile flags) for linux x390x by default.
> But potentially ltgc or similar size-optimizing options could be enabled on other platforms too, and not only debug builds could lose the debug helpers (however in non-debug builds they might be not that important).
> 
> On Windows we already export the debug helper symbols, so it might be good to do this on other platforms, especially Linux, too.

LGTM.

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Marked as reviewed by mdoerr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/29232#pullrequestreview-3661444917