Avoid segfault when executing tests with JDK < 11.0.4

[felixbarny]

What does this PR do?

#1230 required us to update to the latest JDK in order to avoid crashes when executing tests.

I've investigated a little more. While I can't say which parts of the PR triggered the segfault, I can rule out a few options:

• Adding invokedynamic instructions
• Usage of PostProcessor/@AssignTo

The segfault even triggers when only the testLegacyDefaultDisabledInstrumentation test is active in InstrumentationTest and when using @Advice.Return(readOnly = false) instead of @AssignTo.Return.

As described in the JDK tracker https://bugs.openjdk.java.net/browse/JDK-8210457, the issue occurs when there's a retransformation happening concurrently to the StackWalker traversing the stack.

The workaround is to only create the logger once.

Checklist

• This is an enhancement of existing features, or a new feature in existing plugins
  • I have updated CHANGELOG.asciidoc
  • I have added tests that prove my fix is effective or that my feature works
  • Added an API method or config option? Document in which version this will be introduced
  • I have made corresponding changes to the documentation
• This is a bugfix
  • I have updated CHANGELOG.asciidoc
  • I have added tests that would fail without this fix
• This is a new plugin
  • I have updated CHANGELOG.asciidoc
  • My code follows the style guidelines of this project
  • I have made corresponding changes to the documentation
  • I have added tests that prove my fix is effective or that my feature works
  • New and existing unit tests pass locally with my changes
  • I have updated CHANGELOG.asciidoc
  • I have updated supported-technologies.asciidoc
  • Added an API method or config option? Document in which version this will be introduced
  • Added an instrumentation plugin? Describe how you made sure that old, non-supported versions are not instrumented by accident.
• This is something else
  • I have updated CHANGELOG.asciidoc

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• Build Cause: [Branch indexing]

• Start Time: 2020-07-16T11:39:09.545+0000

• Duration: 41 min 26 sec

Test stats 🧪

Test	Results
Failed	0
Passed	1459
Skipped	11
Total	1470