Instrumentation fails on Java 14

Steps to reproduce:
```
git clone https://github.com/i-net-software/JWebAssembly.git
cd JWebAssembly
gradle clean&&gradle test
```
Output:
...Omitted... (Everything normal)
> Task :test
[java14instrumentation.txt](https://github.com/i-net-software/JWebAssembly/files/4689334/java14instrumentation.txt)

I tried commenting out in build.gradle:
```
apply plugin: 'jacoco'
jacocoTestReport {
tasks.coveralls.dependsOn it
reports {
xml.enabled = true // coveralls plugin depends on xml format report
html.enabled = true
}
}
check.dependsOn tasks.coveralls
```

Now the tests are running and some are failing:
[FailingTests.txt](https://github.com/i-net-software/JWebAssembly/files/4689367/FailingTests.txt)
[testReports.zip](https://github.com/i-net-software/JWebAssembly/files/4689383/testReports.zip)

Next I installed java 11:
openjdk 11.0.7-ea 2020-04-14
OpenJDK Runtime Environment (build 11.0.7-ea+9-post-Debian-1)
OpenJDK 64-Bit Server VM (build 11.0.7-ea+9-post-Debian-1, mixed mode, sharing)

Instrumentation failed and those tests, too.

Java 14 Version:
openjdk 14.0.1 2020-04-14
OpenJDK Runtime Environment (build 14.0.1+7-Debian-1)
OpenJDK 64-Bit Server VM (build 14.0.1+7-Debian-1, mixed mode, sharing)

OS:
Linux 5.6.0-1-amd64 #1 SMP Debian 5.6.7-1 (2020-04-29) x86_64 GNU/Linux