Commit 4d3a042da1 missed a corresponding update to win32/makefile.mk
No need to look for Borland's debug symbols files

Commit 378eeda70c missed this.
All modified files in UPSTREAM=>cpan/undef distros are now listed as CUSTOMIZED

All of these modifications already had, or now have, rt.cpan.org tickets
for them requesting that the changes be merged upstream, and the ticket
numbers are now listed in Maintainers.pl alongside each list of CUSTOMIZED
files.

The goal is ultimately to get new CPAN distros rolled for all of these so
that we have no CUSTOMIZED files left (other than a couple of special
cases - libnet, Module::Build and podlators), but there is nothing we can
do at our end to make this happen.
Regen t/porting/customized.dat following f81a37f2d8