[fixes #2327] mostly trivial: Added this. for field access and unified code gen of build() methods for @Builder.

test/transform/resource/after-delombok/BuilderWithNoBuilderMethod.java

@@ -18,7 +18,7 @@ class BuilderWithNoBuilderMethod {
 		}
 		@java.lang.SuppressWarnings("all")
 		public BuilderWithNoBuilderMethod build() {
-			return new BuilderWithNoBuilderMethod(a);
+			return new BuilderWithNoBuilderMethod(this.a);
 		}
 		@java.lang.Override
 		@java.lang.SuppressWarnings("all")