WELD-2498 Expand ClassFileInfo to detect all possible class nesting types.

[manovotn]

We could also add default impl (e.g. simply false) but I don't think it's worth it here.

[nziakova]

Should this be updated in the docs, too?

[manovotn]

It should indeed, thanks!

[manovotn]

Docs are updated as a part of weld/core#1858

[mkouba]

I'd rather introduce a single method that would return the nesting type of the class, something similar to org.jboss.jandex.ClassInfo.NestingType, except that Jandex reports static nested classes as inner classes (see ClassInfo.nestingType() javadoc). Our enum could be something like:

enum NestingType {
  TOP_LEVEL,
  NESTED_INNER,
  NESTED_LOCAL,
  NESTED_ANONYMOUS,
  NESTED_STATIC
}

On the other hand, even with these two additional methods we can distinguish all nesting types:

Type	Test
top level	isTopLevelClass()
inner	!isTopLevelClass() && !isLocalClass() && !isAnonymousClass() && !Modifier.isStatic(getModifiers())
static nested	!isTopLevelClass() && Modifier.isStatic(getModifiers())
inner local	isLocalClass()
inner anonymous	isAnonymousClass()

WDYT?