[test/spec] Audit var-ref cases.

Addresses #311.

Two cases are marked OK.  Filed bug #343.

spec/var-ref.test.sh

@@ -23,7 +23,7 @@ ref=*; printf "|%s" "${!ref}" $'\n'
 |x y|
 ## END
 
-#### var ref with special vars
+#### var ref to $? with '?'
 myfunc() {
   local ref=$1
   echo ${!ref}
@@ -34,6 +34,10 @@ myfunc '?'  # osh doesn't do this dynamically
 myfunc
 0
 ## END
+## N-I osh STDOUT: 
+myfunc
+## END
+## N-I osh status: 1
 
 #### indirection, *then* fancy expansion features
 check_eq() {
@@ -186,21 +190,26 @@ echo done
 ## OK bash stdout: done
 
 #### declare -n and ${!a}
+# NOTE: This is like named-ref.test.sh.  OSH doesn't implement it at all.
+# Maybe we should throw an error on '-n'.
 declare -n a
 a=b
 b=c
 echo ${!a} ${a}
 ## stdout: b c
 
 #### Bad var ref with ${!a}
-#set -o nounset
 a='bad var name'
 echo ref ${!a}
 echo status=$?
 ## STDOUT:
 status=1
 ## END
 
+# this error is fatal in osh
+## OK osh stdout-json: ""
+## OK osh status: 1
+
 #### ${!OPTIND} (used by bash completion
 set -- a b c
 echo ${!OPTIND}

test/spec.sh

@@ -611,7 +611,7 @@ extglob-match() {
 # ${!var} syntax -- oil should replace this with associative arrays.
 # mksh has completely different behavior for this syntax.  Not worth testing.
 var-ref() {
-  sh-spec spec/var-ref.test.sh --osh-failures-allowed 6 \
+  sh-spec spec/var-ref.test.sh --osh-failures-allowed 4 \
     $BASH $OSH_LIST "$@"
 }