[fixes #2838] Handle anonymous classes properly

Generated qualified names (e.g. Outer.Inner) now stop at anonymous
classes instead of adding an empty part. All handlers that add static
fields/methods/types now add error messages instead of generating
invalid code.

test/transform/resource/after-ecj/ConstructorsInAnonymousClass.java

@@ -0,0 +1,38 @@
+import lombok.AllArgsConstructor;
+import lombok.NoArgsConstructor;
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+public class ConstructorsInAnonymousClass {
+  Object annonymous = new Object() {
+    @AllArgsConstructor @RequiredArgsConstructor @NoArgsConstructor class Inner {
+      private String string;
+      private @NonNull String string2;
+      public @java.lang.SuppressWarnings("all") Inner(final String string, final @NonNull String string2) {
+        super();
+        if ((string2 == null))
+            {
+              throw new java.lang.NullPointerException("string2 is marked non-null but is null");
+            }
+        this.string = string;
+        this.string2 = string2;
+      }
+      public @java.lang.SuppressWarnings("all") Inner(final @NonNull String string2) {
+        super();
+        if ((string2 == null))
+            {
+              throw new java.lang.NullPointerException("string2 is marked non-null but is null");
+            }
+        this.string2 = string2;
+      }
+      public @java.lang.SuppressWarnings("all") Inner() {
+        super();
+      }
+    }
+    x() {
+      super();
+    }
+  };
+  public ConstructorsInAnonymousClass() {
+    super();
+  }
+}