Retire U64_TO_DBL and DBL_TO_U64

src/lib/cc/compat_compiler.h

src/lib/tls/tortls.c

src/or/confparse.c

src/or/cpuworker.c

src/or/hibernate.c

src/or/main.c

src/or/rephist.c

src/or/status.c

src/test/test_util.c