Auto merge of #2925 - devnexen:cpuset_size_dfbsd, r=JohnTitor

CPU_SETSIZE constant to dragonflybsd.

Author: bors

libc-test/semver/dragonfly.txt

@@ -145,6 +145,7 @@ CODESET
 CPU_CLR
 CPU_ISSET
 CPU_SET
+CPU_SETSIZE
 CPU_ZERO
 CPUCTL_RSMSR
 CPUCTL_WRMSR

src/unix/bsd/freebsdlike/dragonfly/mod.rs

@@ -1066,6 +1066,8 @@ pub const CPUCTL_MSRSBIT: ::c_int = 0xc0106305;
 pub const CPUCTL_MSRCBIT: ::c_int = 0xc0106306;
 pub const CPUCTL_CPUID_COUNT: ::c_int = 0xc0106307;
 
+pub const CPU_SETSIZE: ::size_t = ::mem::size_of::<::cpumask_t>() * 8;
+
 pub const EVFILT_READ: i16 = -1;
 pub const EVFILT_WRITE: i16 = -2;
 pub const EVFILT_AIO: i16 = -3;