os2: initial implementation for Darwin&BSDs, process API is only thing incomplete

core/os/os2/process_posix_other.odin

@@ -0,0 +1,15 @@
+//+private
+//+build netbsd, openbsd, freebsd
+package os2
+
+import "base:runtime"
+
+_process_info_by_pid :: proc(pid: int, selection: Process_Info_Fields, allocator: runtime.Allocator) -> (info: Process_Info, err: Error) {
+	err = .Unsupported
+	return
+}
+
+_process_list :: proc(allocator: runtime.Allocator) -> (list: []int, err: Error) {
+	err = .Unsupported
+	return
+}