[PATCH] msvcrt: Fix early pipe closing

[Dan Kegel]

On Sat Feb 2, Nguyễn Thái Ngọc Duy wrote:
> Pipes are not like other normal files. If we do not read enough
> bytes, it does not mean it reaches EOF
> ... fixes broken pipe on git-fetch-pack (MinGW port)

This is the same problem as
   http://bugs.winehq.org/show_bug.cgi?id=11187
so it's my fault.  Thanks for the information about
git-fetch-pack failing, and for the proposed fix.

Before we can commit a fix like yours, we need a test case,
so I improved msvcrt/tests/file.c to test EOF on pipes more thoroughly.
It shows your patch was almost right.  I've fixed up your patch
and will send it in.
- Dan