graviton-ready-java: NoClassDefFoundError in JarNativeInfo misses potential native methods

[aidar-stripe]

Describe the bug

When you ask tool to verify N jars, that are dependent on each other, like:

• jar1 -> Class1
• jar2 -> Class2
• jar3 -> Class3

And Class2 has a dependency on Class1 and also contains native methods, JarNativeInfo would try to load Class2, but fail will NoClassDefFound error, that would be ignored: https://github.com/aws/porting-advisor-for-graviton/blob/main/src/advisor/tools/graviton-ready-java/src/main/java/com/amazonaws/labs/GravitonReadyAssessor/JarNativeInfo.java#L185

This just results in skipping some native methods and marking libraries as "good" without them actually being "good".

Proposed fix

It would be better to not try to load class into JVM, but rather parse the bytecode using javassist. That way class could be analyzed for presence of native methods without loading all dependent classes.

[bhallasaksham]

Thank you for your reaching out @aidar-stripe. Our team will take a look at this and get back to you with any comments.