[jdk21u-dev] RFR: 8325530: Vague error message when com.sun.tools.attach.VirtualMachine fails to load agent library

[Daniel Hu]

Clean backport. Fixes a regression in 21: VirtualMachine.loadAgentPath/loadAgentLibrary failing with AgentLoadException doesn't return full error details from AttachListener success case. Change passes GHA and internal Amazon pipelines:  jtreg tier1-4 and tck tests on platforms linux x64, aarch64, aarch32; alpine x64, aarch64; mac aarch64; windows x64.

-------------

Commit messages:
 - Backport fc67c2b4f17216d4adcc0825d0f378ae4f150025

Changes: https://git.openjdk.org/jdk21u-dev/pull/2391/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2391&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325530
  Stats: 150 lines in 6 files changed: 109 ins; 16 del; 25 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2391.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2391/head:pull/2391

PR: https://git.openjdk.org/jdk21u-dev/pull/2391