RFR: 8241066: Shenandoah: fix or cleanup SH::do_full_collection

[Aleksey Shipilev]

On Thu, 16 Oct 2025 19:02:16 GMT, William Kemper <wkemper at openjdk.org> wrote:

> This `ShenandoahHeap::do_full_collection` will never be called by our implementation of `collect_as_vm_thread`.

Marked as reviewed by shade (Reviewer).

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

PR Review: https://git.openjdk.org/jdk/pull/27853#pullrequestreview-3349159907