ash: add a few tests from hush-vars/*

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

shell/ash_test/ash-vars/param_expand_bash_substring.right

@@ -0,0 +1,64 @@
+SHELL: line 1: syntax error: bad substitution
+SHELL: line 1: syntax error: bad substitution
+SHELL: line 1: syntax error: bad substitution
+SHELL: line 1: syntax error: bad substitution
+SHELL: line 1: syntax error: missing '}'
+1    =||
+1:1  =||
+1:1:2=||
+1::2 =||
+1:1: =||
+1::  =||
+1    =|0123|
+1:1  =|123|
+1:1:2=|12|
+1::2 =|01|
+1:1: =||
+1::  =||
+f    =||
+f:1  =||
+f:1:2=||
+f::2 =||
+f:1: =||
+f::  =||
+f    =||
+f:1  =||
+f:1:2=||
+f::2 =||
+f:1: =||
+f::  =||
+f    =|a|
+f:1  =||
+f:1:2=||
+f::2 =|a|
+f:1: =||
+f::  =||
+f    =|0123456789|
+f:1  =|123456789|
+f:1:2=|12|
+f::2 =|01|
+f:1: =||
+f::  =||
+Substrings from special vars
+?    =|0|
+?:1  =||
+?:1:2=||
+?::2 =|0|
+?:1: =||
+?::  =||
+#    =|11|
+#:1  =|1|
+#:1:2=|1|
+#::2 =|11|
+#:1: =||
+#::  =||
+Substrings with expressions
+f            =|01234567|
+f:1+1:2+2    =|2345|
+f:-1:2+2     =|01234567|
+f:1:f        =|1234567|
+f:1:$f       =|1234567|
+f:1:${f}     =|1234567|
+f:1:${f:3:1} =|123|
+f:1:1`echo 1`=|1|
+Done