Revert "Python 3 - Don't add the _d suffix to the symlink on Windows."

This reverts commit e59c95ca936f5a0a8abb987b8605fd8bf82b03b6.

This was a mistake on my part.  The real problem was with my
environment.  I was using a release interpreter to try to load
my debug extension module.  I noticed this after I finally managed
to get into my extension module's init method, and then it segfaulted
with heap errors due to mismatched CRT (debug vs. release)

llvm-svn: 252030