drop IFS-space-colon-3 because dash is the only shell which passes it,

but ksh93 passes ifs.sh which I assume is more correct, and mksh and
ksh93 have the same result for this (as do bash2/4, posh; zsh differs)

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.414 2011/03/06 01:50:08 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.415 2011/03/06 17:06:17 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -2994,23 +2994,6 @@ stdin:
 expected-stdout:
 	 <:>
 ---
-name: IFS-space-colon-3
-description:
-	Simple test, IFS=<white-space>:
-	pdksh fails both of these tests
-	not sure whether #2 is correct
-stdin:
-	showargs() { for i; do echo -n " <$i>"; done; echo; }
-	IFS="$IFS:"
-	x=
-	set --
-	showargs "$x$@" 1
-	showargs "$@$x" 2
-expected-fail: yes
-expected-stdout:
-	 <> <1>
-	 <> <2>
----
 name: IFS-space-colon-4
 description:
 	Simple test, IFS=<white-space>: