Before this commit, anonymous classes could throw an
unexpected NullPointerException in
ReflectionsHint#registerType and lambdas entries could
be created in the related generated reflect-config.json.
This commit refines how anonymous classes are handled by
explicitly checking for null class and canonical name in
ReflectionTypeReference#of, while skipping such class in
ReflectionHints#registerType in order to keep a lenient
behavior.
Closes gh-29774
dbbebf541d