workaround glibc posix violation with regards to suseconds_t According to posix tv_usec has type suseconds_t, however glibc with time64 violates this defining tv_usec as time_t (a 64-bit type) while defining suseconds_t as a 32-bit type.
Most C programs don't care about this difference because C allows implicit conversion between different sized integers but rust does not..
This patch works around the issue by allowing the compiler to infer the type to convert to rather than hardcoding suseconds_t.
