[fixes #3225] Handle ambiguous extension methods

test/transform/resource/before/ExtensionMethodAmbiguousFunctional.java

@@ -0,0 +1,20 @@
+//version 8:
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import lombok.experimental.ExtensionMethod;
+
+@ExtensionMethod({ExtensionMethodAmbiguousFunctional.Extensions.class})
+class ExtensionMethodAmbiguousFunctional {
+	public void test() {
+		"".ambiguous(System.out::println);
+	}
+	
+	static class Extensions {
+		public static <T, R> void ambiguous(T t, Function<T, R> function) {
+		}
+		
+		public static <T> void ambiguous(T t, Consumer<T> function) {
+		}
+	}
+}