Suggest quoting expansions in for loop globs

src/ShellCheck/ASTLib.hs

@@ -435,3 +435,12 @@ pseudoGlobIsSuperSetof = matchable
 
 wordsCanBeEqual x y = fromMaybe True $
     liftM2 pseudoGlobsCanOverlap (wordToPseudoGlob x) (wordToPseudoGlob y)
+
+-- Is this an expansion that can be quoted,
+-- e.g. $(foo) `foo` $foo (but not {foo,})?
+isQuoteableExpansion t = case t of
+    T_DollarExpansion {} -> True
+    T_DollarBraceCommandExpansion {} -> True
+    T_Backticked {} -> True
+    T_DollarBraced {} -> True
+    _ -> False