libfst is no longer included in gtkwave and instead has its own repo. There has also been some refactoring, so the patches need to update to match, as does sim.cc.
I think what's happening here is that the _WIN64 fix is correct for 64bit windows, but (for whatever reason) the visual studio build is targeting 32bit windows, so the fix is unnecessary, but the upstream fix doesn't expect to be targeting 32bit windows and assumes all windows builds are 64bit... so fix that.
