autofuzz: Filter out unnamed classes

Classes without a canonical name cannot be instantiated by reproducers
and thus also shouldn't be used by Autofuzz. If we find constructing
them useful, we should instead look for factory methods.

Author: fmeum

src/main/java/com/code_intelligence/jazzer/autofuzz/Meta.java

@@ -601,6 +601,9 @@ Object consume(FuzzedDataProvider data, Type genericType, AutofuzzCodegenVisitor
           implementingClasses = children.getStandardClasses()
                                     .filter(info -> !Modifier.isAbstract(info.getModifiers()))
                                     .filter(info -> lookup.isAccessible(info, info.getModifiers()))
+                                    // Filter out anonymous and local classes, which can't be
+                                    // instantiated in reproducers.
+                                    .filter(info -> info.getName() != null)
                                     .loadClasses();
           implementingClassesCache.put(type, implementingClasses);
         }