Buildbot should zip up Visual Studio Win64 binaries, too.

build-scripts/windows-buildbot-zipper.bat

@@ -3,11 +3,16 @@ rem just a helper batch file for collecting up files and zipping them.
 rem usage: windows-buildbot-zipper.bat <zipfilename>
 rem must be run from root of SDL source tree.
 
-IF EXIST VisualC\Win32\Release GOTO okaydir
+IF EXIST VisualC\Win32\Release GOTO okaywin32dir
 echo Please run from root of source tree after doing a Release build.
 GOTO done
 
-:okaydir
+:okaywin32dir
+IF EXIST VisualC\Win64\Release GOTO okaydirs
+echo Please run from root of source tree after doing a Release build.
+GOTO done
+
+:okaydirs
 erase /q /f /s zipper
 IF EXIST zipper GOTO zippermade
 mkdir zipper
@@ -18,10 +23,14 @@ cd SDL
 mkdir include
 mkdir lib
 mkdir lib\win32
+mkdir lib\win64
 copy ..\..\include\*.h include\
 copy ..\..\VisualC\Win32\Release\SDL2.dll lib\win32\
 copy ..\..\VisualC\Win32\Release\SDL2.lib lib\win32\
 copy ..\..\VisualC\Win32\Release\SDL2main.lib lib\win32\
+copy ..\..\VisualC\x64\Release\SDL2.dll lib\win64\
+copy ..\..\VisualC\x64\Release\SDL2.lib lib\win64\
+copy ..\..\VisualC\x64\Release\SDL2main.lib lib\win64\
 cd ..
 zip -9r ..\%1 SDL
 cd ..