add clcache to Windows build

Author: Daniel Kroening

buildspec-windows.yml

@@ -7,7 +7,8 @@ phases:
       - cyg-get bash patch bison flex make wget perl
       - nuget install clcache -OutputDirectory "c:\tools\cygwin\bin" -ExcludeVersion
       - cmd /c 'dir c:\tools\cygwin\bin\clcache'
-      - Move-Item -Path 'c:\tools\cygwin\bin\clache\clcache.exe' -Destination 'c:\tools\cygwin\bin'
+      - cmd /c 'dir c:\tools\cygwin\bin\clcache\clcache-4.1.0'
+      - Move-Item -Path 'c:\tools\cygwin\bin\clache\clcache-4.1.0\clcache.exe' -Destination 'c:\tools\cygwin\bin'
 
   build:
     commands: