fix: handle type alias declaration for PrimitiveType

gnovm/pkg/gnolang/preprocess.go

@@ -2352,6 +2352,8 @@ func preprocess1(store Store, ctx BlockNode, n Node) Node {
 						// }
 						*dst = *dt2
 					}
+				case PrimitiveType:
+					dst = tmp.(PrimitiveType)
 				default:
 					panic(fmt.Sprintf("unexpected type declaration type %v",
 						reflect.TypeOf(dst)))
@@ -4283,6 +4285,8 @@ func tryPredefine(store Store, last BlockNode, d Decl) (un Name) {
 							// predefineNow preprocessed dependent types.
 							panic("should not happen")
 						}
+					} else if _, ok := t.(PrimitiveType); ok {
+						// if primitive type then do nothing
 					} else {
 						// all names are declared types.
 						panic("should not happen")

gnovm/tests/files/type40.gno

@@ -0,0 +1,16 @@
+package main
+
+type (
+	Number  = int32
+	Number2 = Number
+)
+
+func f(n Number) { println(n) }
+
+func main() {
+	var n Number = 5
+	f(n)
+}
+
+// Output:
+// 5