Sort ctype_defs in dependency order after specialisation

We now generate anonymous types in the correct order, but post specialisation more dependencies can occur between named types, so an additional
sorting step is needed to ensure that these happen in the correct order. In theory we could end up with circular dependencies here that don't exist
at the Sail source level, but this shouldn't occur often (or ever) in practice. I think this is fixable but it would require some code generator
changes.

1 files changed, 27 insertions, 0 deletions

diff --git a/test/c/poly_union_rev.sail b/test/c/poly_union_rev.sail
new file mode 100644
index 00000000..bc654808
--- /dev/null
+++ b/test/c/poly_union_rev.sail
@@ -0,0 +1,27 @@
+default Order dec
+
+val print = "print_endline" : string -> unit
+
+union option ('a : Type) = {
+  Some : 'a,
+  None : unit
+}
+
+union ast = {
+  HCF : unit
+}
+
+val decode : unit -> option(ast)
+
+function decode() = Some(HCF())
+
+val main : unit -> unit
+
+function main() = {
+  let instr = decode();
+  match instr {
+    Some(HCF()) => print("HCF"),
+    Some(_) => print("Some(_)"),
+    None() => print("None")
+  }
+}
\ No newline at end of file