Crash when trying to define a method macro that isn't @construct but has no arguments.

test/test_suite/macro_methods/macro_methods_no_args.c3

@@ -0,0 +1,17 @@
+import std::io;
+// Issue #1990
+struct Foo
+{
+	uint field;
+}
+
+macro Foo.bar() // #error: A method must start with an argument
+{
+	io.printn("UwU");
+}
+
+fn void main()
+{
+	Foo foo = {};
+	foo.bar();
+}