run clang tests under sanitise=ON

https://clang.llvm.org/docs/AddressSanitizer.html

If a bug is detected, the program will print an error message to stderr and exit with a non-zero exit code. AddressSanitizer exits on the first detected error.

https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html

^ check how to enforce exit code failure, perhaps use WERROR=ON to determinate whether to disable recovery