Fix VM memory allocation optimizations by reducing what we allocate on the heap

internal/object/environment.go

@@ -39,7 +39,7 @@ func (e *Environment) ExportedHash() *Hash {
 	pairs := make(map[HashKey]HashPair)
 	for k, v := range e.store {
 		if unicode.IsUpper(rune(k[0])) {
-			s := &String{Value: k}
+			s := String{Value: k}
 			pairs[s.HashKey()] = HashPair{Key: s, Value: v}
 		}
 	}