fix failed indirection of unassigned function results

src/Convert/Scoper.hs

@@ -520,7 +520,11 @@ scopeModuleItem declMapperRaw moduleItemMapper genItemMapper stmtMapperRaw =
         redirectTFDecl :: Type -> Identifier -> ScoperT a m (Type, Identifier)
         redirectTFDecl typ ident = do
             res <- declMapper $ Variable Local typ ident [] Nil
-            let Variable Local newType newName newRanges Nil = res
+            (newType, newName, newRanges) <-
+                return $ case res of
+                    Variable Local t x r Nil -> (t, x, r)
+                    Net Local TWire DefaultStrength t x r Nil -> (t, x, r)
+                    _ -> error "redirectTFDecl invariant violated"
             return $ if null newRanges
                 then (newType, newName)
                 else

test/core/func_no_asgn.sv

@@ -0,0 +1,8 @@
+module top;
+    function automatic bit foo;
+        input integer x;
+        // no return
+    endfunction
+    bit x;
+    assign x = foo(0);
+endmodule

test/core/func_no_asgn.v

@@ -0,0 +1,4 @@
+module top;
+    wire x;
+    assign x = 1'bx;
+endmodule