feature-test build rules fails to preserve ThreadSanitizer options (-fsanitizer=thread)
$ ./feature-test
dyld: lazy symbol binding failed: Symbol not found: ___tsan_init
Referenced from: /Users/ondrej/Projects/bind9/lib/isc/.libs/libisc.1503.dylib
Expected in: flat namespace
dyld: Symbol not found: ___tsan_init
Referenced from: /Users/ondrej/Projects/bind9/lib/isc/.libs/libisc.1503.dylib
Expected in: flat namespace
Abort trap: 6