[ VM / NNBD ] Fixed standalone_2/io/file_test
[ VM / NNBD ] Fixed standalone_2/io/file_test

Change-Id: I28dbe124125425bfa2460f30be974e165c6bdf7c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/137360
Reviewed-by: Ryan Macnak <d738b7f001baf9789095d7dc549cff6de60b011d@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk