ash testsuite: add most of hust tests which pass for ash

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/ash_test/ash-vars/var_expand_on_ifs.right

@@ -0,0 +1,9 @@
+1 a b c
+2 a + b c
+3 a b c
+4 a  b c
+5 a  b c
+6 a b + c
+7 a b c
+8 a b  c
+9 a b  c