Bidirectional port gets GCed before the operation completed

[Takashi Kato]

(http-get "github.com"
      "/ktakashi/sagittarius-scheme/archive/master.zip"
      :secure #t
      :receiver (http-binary-receiver))

The above may or may not finish properly. When it fails, it shows an invalid apply error due to the GCed object.

[Takashi Kato]

Adding bidirectional buffered port specific finalizer (Fixes #290) Previous implementation uses non-pointer member address to register a finalizer which seems make GC confused.

→ <<cset 18b64c6eb1b2>>