Setting this option enables address sanitizer and undefined behavior
sanitizer, when available for the given compiler & platform.
It does not currently check whether the architecture is supported,
as CMake does not offer an easy way how to check it. Since we are
mostly developing for x86 & amd64 this is not a huge problem and it's
also a developer only setting.
* [appveyor] Install clcache with nuget
* [appveyor] Keep clcache in the appveyor jobs
* [appveyor] Print clcache stats after compiling the project
* Use CLCACHE_PATH env variable to find clcache
