You need to iterate through each dependent DLL using objdump to get the full list. This is automated in pp_simple and pp_autolink, so perhaps give them a try.

FWIW, I get this set on Strawberry Perl 5.28 for a script that just does use GD; print "1";.

 libiconv-2__.dll
 zlib1__.dll
 libbz2-1__.dll
 libgd-3__.dll
 libfreetype-6__.dll
 libpng16-16__.dll
 liblzma-5__.dll
 libxpm__.dll
 libtiff-5__.dll
 libjpeg-9__.dll
[download]

This is similar to the set provided by haj in 11117362 but missing libgraphite and libharfbuzz, presumably because I used a simpler script.

Update: I see marto has already provided links to pp_simple and pp_autolink info in 11117346.