more forward declarations

examples/issue-0002.sx

@@ -0,0 +1,25 @@
+#import "modules/std.sx";
+
+// Issue: nested field assignment through pointer
+// self.inner.field = value should work when self is a pointer
+
+Inner :: struct {
+    len: s64;
+    cap: s64;
+}
+
+Outer :: struct {
+    inner: Inner;
+    count: s64;
+
+    reset :: (self: *Outer) {
+        self.inner.len = 0;   // error: field assignment target must be a variable
+        self.count += 1;
+    }
+}
+
+main :: () {
+    o := Outer.{ inner = Inner.{ len = 5, cap = 10 }, count = 0 };
+    o.reset();
+    print("{}\n", o.inner.len);
+}