fix: untyped to interface check (#2042)

solves [issue](#2023)

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs

---------

Co-authored-by: deelawn <[email protected]>

gnovm/pkg/gnolang/preprocess.go

@@ -2472,6 +2472,9 @@ func convertIfConst(store Store, last BlockNode, x Expr) {
 
 func convertConst(store Store, last BlockNode, cx *ConstExpr, t Type) {
 	if t != nil && t.Kind() == InterfaceKind {
+		if cx.T != nil {
+			checkType(cx.T, t, false)
+		}
 		t = nil // signifies to convert to default type.
 	}
 	if isUntyped(cx.T) {

gnovm/tests/files/fun27.gno

@@ -0,0 +1,16 @@
+package main
+
+type Foo interface {
+	foo()
+}
+
+func NewSet() Foo {
+	return 1
+}
+
+func main() {
+	NewSet()
+}
+
+// Error:
+// main/files/fun27.gno:8: <untyped> bigint does not implement main.Foo