When running the ARM perlasm files on Windows, close STDOUT fails. There appears to be some weird quirk on Windows when one replaces STDOUT with a pipe. The x86_64.pl files all avoid this by opening OUT and then setting *STDOUT=*OUT. Align all the ARM files with that pattern. See https://ci.appveyor.com/project/conscrypt/conscrypt Change-Id: Ibee9427a05d806f7f23a6d9817394cfabf2f534a Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/37324 Reviewed-by: Kenny Root <kroot@google.com> Reviewed-by: Adam Langley <agl@google.com> Commit-Queue: Adam Langley <agl@google.com>