git: openjdk/jdk21: 8309956: Shenandoah: Strengthen the mark word check in string dedup

[Aleksey Shipilev]

Changeset: 0ac92753
Author:    Aleksey Shipilev <shade at openjdk.org>
Date:      2023-06-15 07:51:16 +0000
URL:       https://git.openjdk.org/jdk21/commit/0ac92753dd3991123cbbf72cc812c158f68fe6e1

8309956: Shenandoah: Strengthen the mark word check in string dedup

Reviewed-by: rkennke
Backport-of: 57b8251241e2044d5039ce162bf4637a9b2e5466

! src/hotspot/share/gc/shenandoah/shenandoahStringDedup.inline.hpp