[jdk19] RFR: 8289278: Suspend/ResumeAllVirtualThreads need both can_suspend and can_support_virtual_threads

[Alan Bateman]

This is spec only change to the JVM TI spec. The `SuspendAllVirtualThreads` and `ResumeAllVirtualThreads` functions added in Java 19 currently specify that they require one of the capabilities `can_suspend` or `can_support_virtual_threads`. This is not correct as both capabilities are required.

The issue is in the XSL used to generate the spec, and specifically the `capabilities` template where it emits different text when the number of required capabilities is not 0 or 1. Additionally, the description of the `can_support_virtual_threads` is overridden in both functions to avoid making it appear that the capability on its own is needed to use these functions.

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Commit messages:
 - Override can_support_virtual_threads description
 - Initial commit

Changes: https://git.openjdk.org/jdk19/pull/82/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=82&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289278
  Stats: 4 lines in 2 files changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk19/pull/82.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/82/head:pull/82

PR: https://git.openjdk.org/jdk19/pull/82