the previous commit was wrong.

Replace StringBuffer with StringBuilder, other minor String optimizations

Replace array copy loops with System.arraycopy

Only wrap the method name if the method doesn't come from the same declaring class

Fix renaming of classes in presence of generic signatures and nested classes.
This pull request has some problems but I'll fix them later.

fixes a bug of ClassFile#renameClass(), some imports could not be successfully renamed.

Lower requirement for an extra type in constructor to Java 7-

Using TCK Tested JDK builds of OpenJDK

Remove redundant type check

The same condition is repeated twice (caught by FindBugs.)

The AdoptOpenJDK has been discontinued since July 2021. When using Zulu you get all the latest updated (TCK Tested) builds for all versions of OpenJDK. 

Also added are fixed (major) release version(s) such as 11.0.3. This is often a good practice whenever a build/test triggers (push/pull events) this can determine if the latest JDK (11) had failed the build vs something in your code that caused it. For example, when building with JDK 11.0.3 (fixed version) the build passes (green) and JDK 11 fails (red) will mean that the latest JDK (11) was the cause and not your code. 



Note: Other distributions such as Temurin do not support archived fixed release prior to Sept. 2021.