* removed build type ASAN. Targets should define ASan usage by sanitize_address
  function
* compiler flags will be searched by compiler instead of per language
* FindASan warns, if a target can't be sanitized because of incompatible
  compilers
* added some helper functions

Thus C can be mixed with Fortran and the objects can be build with different
compilers, not both may support AddressSanitizer.

Instead of fix checking for C and CXX compilers, all enabled languages will be
tested now.

Older CMake versions are not capable of continue in foreach functions.

Set the HAVE_MEMORY_SANITIZER and HAVE_ADDRESS_SANITIZER cache entries.

Don't emit an error for deleting an object with a nonvirtual dtor.

These were (inconsistently) not being set as opposed to
HAVE_THREAD_SANITIZER and HAVE_UNDEFINED_BEHAVIOUR_SANITIZER

We want that behaviour at runtime to make sure ubsan works