RFR: 8367862: debug.cpp: Do not print help message for methods not compiled in

[Paul Hohensee]

On Wed, 17 Sep 2025 11:27:27 GMT, Kerem Kat <krk at openjdk.org> wrote:

> The `help` command in `debug.cpp` was out of date, listing only a fraction of the available functions. This and other commands callable from gdb via `call help()`.
> 
> I added all commands to the help message, except `pns2` as it is documented as not being useful when called from gdb.
> 
> Also fixed is the message for the conditional `pns` command appearing in PRODUCT builds.

Marked as reviewed by phh (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/27341#pullrequestreview-3240752187