'main': Highlight named fd redirections.

Merge remote-tracking branch 'danielsh/i238-named-fd-redirection-v1'

* danielsh/i238-named-fd-redirection-v1:
  'main': Tighten condition.
  noop: Tweak condition at Matthew's suggestion
  'main': Highlight named fd redirections.

highlighters/main/test-data/exec-redirection1.zsh

@@ -31,8 +31,8 @@ BUFFER='exec {foo}>&/tmp ls'
 
 expected_region_highlight=(
   "1 4 precommand" # exec
-  "6 10 redirection 'issue #238'" # {foo}
+  "6 10 named-fd" # {foo}
   "11 12 redirection" # >&
   "13 16 path" # /tmp
-  "18 19 command 'issue #238'" # ls
+  "18 19 command" # ls
 )