patch 9.0.1657: one more syntax test depends on the system

Problem:    One more syntax test depends on the system.
Solution:   Use "dash" instead of "sh".

runtime/syntax/testdir/dumps/sh_05_00.dump

@@ -1,4 +1,4 @@
->#+0#0000e05#ffffff0|!|/|b|i|n|/|s|h| |-|x| +0#0000000&@62
+>#+0#0000e05#ffffff0|!|/|b|i|n|/|d|a|s|h| |-|x| +0#0000000&@60
 |#+0#0000e05&| |s|h|5| +0#0000000&@69
 |#+0#0000e05&| |N|o|t|e| |t|h|a|t| |t|h|i|s| |i|s| |s|p|e|c|i|a|l| |f|o|r| |s|h|.| |k|s|h| |w|i|l@1| |b|e| |a|n| |e|x|t|r|a| |f|i|l|e| |l|a|t|e|r|.| +0#0000000&@6
 |#+0#0000e05&| |N|o|t|e| |t|o@1|,| |t|h|a|t| |s|h| |a|n|d| |k|s|h| |a|l@1|o|w| |$|{|v|a|r|:|-|s|u|b|}| |a|s| |w|e|l@1| |a|s| |$|{|v|a|r|-|s|u|b|}|!| +0#0000000&@6

runtime/syntax/testdir/input/sh_05.sh

@@ -1,4 +1,4 @@
-#!/bin/sh -x
+#!/bin/dash -x
 # sh5
 # Note that this is special for sh. ksh will be an extra file later.
 # Note too, that sh and ksh allow ${var:-sub} as well as ${var-sub}!

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1657,
 /**/
     1656,
 /**/