Failure recovering connection on Windows

Moved from https://github.com/haskell/cabal/issues/2035.

Most pertinent: compiling and running [this program](https://gist.github.com/23Skidoo/c8d6ab1684ea11195a04) with GHC 7.8.3 produces the following on my Windows 8.1 x64 machine. I have tried to reproduce on VMs but can't.

```
http-test> ghc --make Main.hs -o test.exe -prof -auto-all -caf-all
[1 of 1] Compiling Main ( Main.hs, Main.o )
Linking test.exe ...

http-test> .\test.exe +RTS -xc
Trying to download http://hackage.haskell.org/packages/archive/00-index.tar.gz
Sending:
GET /packages/archive/00-index.tar.gz HTTP/1.1
Host: hackage.haskell.org
User-Agent: cabal-install/1.18.0.5

Creating new connection to hackage.haskell.org
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
Received:
HTTP/1.1 301 Moved Permanently
Server: nginx/1.6.0
Date: Mon, 18 Aug 2014 22:29:21 GMT
Content-Type: text/plain; charset=UTF-8
Connection: keep-alive
Location: /packages/index.tar.gz
Content-Length: 0

301 - redirect
Redirecting to http://hackage.haskell.org/packages/index.tar.gz ...
Sending:
GET /packages/index.tar.gz HTTP/1.1
Host: hackage.haskell.org
User-Agent: cabal-install/1.18.0.5

Recovering connection to hackage.haskell.org
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
Main.main,
called from :Main.CAF:main
test.exe: : hGetBufSome: failed (Unknown error)
```

Start with the linked reproduction program and run the shown GHC 7.8.3 command on Windows, focusing on the connection-recovery step after the HTTP redirect. The issue names no repository file or test; done means the Windows request no longer fails with the reported socket error and the behavior is covered by an appropriate regression test.

Written by the indexing model from the issue text.