Add a test for Py_ssize_t. Correct typo in getargs.c.
diff --git a/Python/getargs.c b/Python/getargs.c
index 8143d33..e6f607a 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -647,10 +647,10 @@
 		Py_ssize_t *p = va_arg(*p_va, Py_ssize_t *);
 		Py_ssize_t ival;
 		if (float_argument_error(arg))
-			return converterr("integer<i>", arg, msgbuf, bufsize);
+			return converterr("integer<n>", arg, msgbuf, bufsize);
 		ival = PyInt_AsSsize_t(arg);
 		if (ival == -1 && PyErr_Occurred())
-			return converterr("integer<i>", arg, msgbuf, bufsize);
+			return converterr("integer<n>", arg, msgbuf, bufsize);
 		*p = ival;
 		break;
 	}