[jdk21u-dev] RFR: 8370214: [21u] Remove -Xdebug and -Xnoagent from tests: backport parts of 8227229 and 8312072

[Goetz Lindenmaier]

This is a backport of the test parts of 

[8227229: Deprecate the launcher -Xdebug/-debug flags that have not done anything since Java 6](https://bugs.openjdk.org/browse/JDK-8227229)
and
[8312072: Deprecate for removal the -Xnoagent option](https://bugs.openjdk.org/browse/JDK-8312072)

I prepared two commits to separate the edits of each of these.

Backporting these changes makes 
  [8327704: Update nsk/jdi tests to use driver instead of othervm](https://bugs.openjdk.org/browse/JDK-8327704)
a clean backport.  As 8327704 is huge, it would be quite unpleasant to review.

Removing the usage of the options in 21 is fine as the effect of these options has been removed before 21.
I do not and can not backport the deprecation part of the change.

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Commit messages:
 - backport usages of flag -Xdebug, see 8227229: Deprecate the launcher -Xdebug/-debug flags that have not done anything since Java 6
 - backport test parts of 8312072: Deprecate for removal the -Xnoagent option

Changes: https://git.openjdk.org/jdk21u-dev/pull/2353/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2353&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8370214
  Stats: 40 lines in 20 files changed: 0 ins; 1 del; 39 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2353.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2353/head:pull/2353

PR: https://git.openjdk.org/jdk21u-dev/pull/2353