try again to get a 64bit build

appveyor.yml

@@ -37,7 +37,7 @@ install:
       )
     - 7z x "opam64.tar.xz" -so | 7z x -aoa -si -ttar
     - '%CYG_ROOT%/bin/bash -lc "cd \"$OLDPWD\" && bash opam64/install.sh"'
-    - '%CYG_ROOT%/bin/bash -lc "opam init mingw \"https://github.com/fdopen/opam-repository-mingw.git\" --comp 4.02.3+mingw32c --switch 4.02.3+mingw32c --auto-setup --yes"'
+    - '%CYG_ROOT%/bin/bash -lc "opam init mingw \"https://github.com/fdopen/opam-repository-mingw.git\" --comp 4.02.3+mingw64c --switch 4.02.3+mingw64c --auto-setup --yes"'
     - '%CYG_ROOT%/bin/bash -lc "opam install camlp4 --yes"'
     # Install neko
     - choco install neko --prerelease --ignore-dependencies -s 'https://ci.appveyor.com/nuget/neko' -y
@@ -55,7 +55,7 @@ install:
     - cmd: mklink C:\Python34-x64\python3.exe C:\Python34-x64\python.exe
     - set PATH=%PATH%;C:\Python34-x64
     # expose the dll files
-    - set "PATH=%PATH%;%CYG_ROOT%/usr/i686-w64-mingw32/sys-root/mingw/bin"
+    - set "PATH=%CYG_ROOT%/usr/x86_64-w64-mingw32/sys-root/mingw/bin;%PATH%"
     - choco install awscli
 
 build_script: