Improve error messages by citing syntax in more of them.
[pspp] / tests / language / control /
drwxr-xr-x   ..
-rw-r--r-- 51956 define.at
-rw-r--r-- 3173 do-if.at
-rw-r--r-- 3532 do-repeat.at
-rw-r--r-- 6356 loop.at
-rw-r--r-- 1254 temporary.at