libsanitizer - remove reference to __cxa_rethrow_primary_exception.
For some Darwin versions the absence of the rethrow_primary_exception
symbol causes almost all sanitizer tests to fail.
The symbol is not present in libstdc++ and, therefore is is correct to
remove the reference to it for all platforms. We do this by adding a
new guard "ASAN_HAS_CXA_RETHROW_PRIMARY_EXCEPTION".