BUG #13447: Zombie postgres.exe processes

The following bug has been logged on the website:

Bug reference:      13447
Logged by:          Paul
Email address:      m8r-geob63@mailinator.com
PostgreSQL version: 9.4.1
Operating system:   Win 7 x64
Description:

Postgres.exe instances are being "zombified" after large number of rows (few
million) are inserted.  The instances will then stick around generally
holding onto 400-600 MB of RAM.  These instances no longer show up in the
pgAdmin "Server Status" window.  Closing all of the applications that were
using Posgres does not clear these from memory.  The only way I can clear
these is to actually restart the Postgres service.

My application is using the libpq library for database operations and it
performs block transactions based on number of rows ready to be committed or
length of time since last commit.  I can easily reproduce this problem so
it's not a one off occurrence.