Fixed incorrect register lifetime in for loops

tests/programs_test.go

@@ -62,6 +62,7 @@ var programs = []struct {
 	{"loop-lifetime", 0},
 	{"loop-in-loop", 0},
 	{"for", 0},
+	{"fibonacci", 0},
 	{"memory-free", 0},
 	{"out-of-memory", 0},
 	{"index-static", 0},