fix: Fixed a compilation issue with send_const_string.

`send` now automatically uses `send_const_string` when appropriate.

zmq.odin

@@ -115,6 +115,7 @@ connect :: proc(s: Socket, addr: string, allocator := context.temp_allocator) ->
 
 send :: proc {
 	send_bytes,
+	send_const_string,
 	send_string,
 }
 
@@ -136,17 +137,12 @@ send_const :: proc {
 }
 
 send_const_string :: proc(s: Socket, $str: string, flags: Flags = {}) -> (int, Error) {
-	n := _send_const(s, rawptr($str), len($str), flags)
-	if n < 0 {
-		return -1, last_error()
-	}
-
-	return int(n), nil
+	return send_const_bytes(s, transmute([]byte)str, flags)
 }
 
 // buf must have @(rodata) or global lifetime.
 send_const_bytes :: proc(s: Socket, buf: []byte, flags: Flags = {}) -> (int, Error) {
-	n := _send_const(s, rawptr(&buf[0]), len(buf), flags)
+	n := _send_const(s, rawptr(&buf[0]), c.size_t(len(buf)), flags)
 	if n < 0 {
 		return -1, last_error()
 	}