sh: Add test for ${01} and ${010} that already works.

Although it is probably unwise to use this, POSIX is clear that leading
zeroes are permitted in positional parameters (and do not indicate octal).

Such positional parameters are checked for being unset and/or null
correctly, but their value is incorrectly expanded.

bin/sh/tests/parameters/Makefile

@@ -13,6 +13,7 @@ FILES+=		optind1.0
 FILES+=		optind2.0
 FILES+=		positional1.0
 FILES+=		positional2.0
+FILES+=		positional3.0
 FILES+=		pwd1.0
 FILES+=		pwd2.0
 

bin/sh/tests/parameters/positional3.0

@@ -0,0 +1,4 @@
+# $FreeBSD$
+
+r=$(${SH} -c 'echo ${01:+yes}${010:+yes}' '' a '' '' '' '' '' '' '' '' b)
+[ "$r" = yesyes ]