RFR: 8332697: ubsan: shenandoahSimpleBitMap.inline.hpp:68:23: runtime error: signed integer overflow: -9223372036854775808 - 1 cannot be represented in type 'long int'

[William Kemper]

Clean backport, fixes ubsan error.

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Commit messages:
 - Backport 57c1db5843db5f2c864318f3234767f436a836e3

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/115/files
  Webrev: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=115&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8332697
  Stats: 34 lines in 3 files changed: 7 ins; 0 del; 27 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/115.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/115/head:pull/115

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/115