fix(gnovm): make Stacktrace correctly handle panics with `len(Stmts…

…) == 0` (#3273)

While finalizing the realm, all statements in the machine have been
popped out. A necessary check must be performed during stack trace
handling.
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- [ ] Added new tests, or not needed, or not feasible
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Co-authored-by: Petar Dambovaliev <[email protected]>

gnovm/pkg/gnolang/machine.go

@@ -401,7 +401,7 @@ func destar(x Expr) Expr {
 // Stacktrace returns the stack trace of the machine.
 // It collects the executions and frames from the machine's frames and statements.
 func (m *Machine) Stacktrace() (stacktrace Stacktrace) {
-	if len(m.Frames) == 0 {
+	if len(m.Frames) == 0 || len(m.Stmts) == 0 {
 		return
 	}