posix: add package

core/sys/posix/sys_un.odin

@@ -0,0 +1,17 @@
+package posix
+
+import "core:c"
+
+// sys/un.h = definitions for UNIX domain sockets
+
+when ODIN_OS == .Darwin || ODIN_OS == .FreeBSD || ODIN_OS == .NetBSD || ODIN_OS == .OpenBSD {
+
+	sockaddr_un :: struct {
+		sun_len:    c.uchar,     /* sockaddr len including nil */
+		sun_family: sa_family_t, /* [PSX] address family */
+		sun_path:   [104]c.char, /* [PSX] socket pathname */
+	}
+
+} else {
+	#panic("posix is unimplemented for the current target")
+}