[fixes #3463] Support argument widening for extension methods

test/transform/resource/before/ExtensionMethodWidening.java

@@ -0,0 +1,15 @@
+import lombok.experimental.ExtensionMethod;
+
+@ExtensionMethod({ExtensionMethodWidening.Extensions.class})
+class ExtensionMethodWidening {
+	public void test() {
+		String string = "test";
+		string.widening(1);
+	}
+	
+	static class Extensions {
+		public static String widening(String string, long a) {
+			return string + " " + a;
+		}
+	}
+}