[jdk21u] RFR: 8313656: assert(!JvmtiExport::can_support_virtual_threads()) with -XX:-DoJVMTIVirtualThreadTransitions

[Aleksey Shipilev]

Clean backport to improve Loom reliability.

Additional testing:
 - [x] macos-aarch64-server-fastdebug, `jdk_loom hotspot_loom`
 - [x] macos-aarch64-server-fastdebug, `serviceability/jvmti`

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Commit messages:
 - Backport b38bcae1bad399d0a3ffc091835bf89140550bc2

Changes: https://git.openjdk.org/jdk21u/pull/217/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=217&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313656
  Stats: 53 lines in 3 files changed: 47 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk21u/pull/217.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/217/head:pull/217

PR: https://git.openjdk.org/jdk21u/pull/217