Add 64-bit DD buildbot

appveyor.yml

@@ -31,6 +31,8 @@ cache:
 install:
 - if [%CONFIGURATION%] == [SDL64] ( set "X86_64=1" )
 - if [%CONFIGURATION%] == [SDL64] ( set "CONFIGURATION=SDL" )
+- if [%CONFIGURATION%] == [DD64] ( set "X86_64=1" )
+- if [%CONFIGURATION%] == [DD64] ( set "CONFIGURATION=DD" )
 - if [%X86_64%] == [1] ( set "MINGW_SDK=%MINGW_SDK_64%" )
 - if [%X86_64%] == [1] ( set "CCACHE_CC=%CCACHE_CC_64%" )
 
@@ -50,10 +52,12 @@ configuration:
 - SDL
 - SDL64
 - DD
+- DD64
 
 matrix:
   allow_failures:
     - configuration: DD
+    - configuration: DD64
 
 before_build:
 - set "Path=%MINGW_SDK%\bin;%Path%"