sys/info: populate cpu.physical_cores and cpu.logical_cores on Darwin

core/sys/info/cpu_darwin.odin

@@ -0,0 +1,12 @@
+package sysinfo
+
+import "core:sys/unix"
+
+@(init, private)
+init_cpu_core_count :: proc "contextless" () {
+	physical, logical: i64
+	unix.sysctlbyname("hw.physicalcpu", &physical)
+	unix.sysctlbyname("hw.logicalcpu", &logical)
+	cpu.physical_cores = int(physical)
+	cpu.logical_cores  = int(logical)
+}