shell-completion: systemd-analyze verify, systemctl link

Some zsh completion helpers were not installed, so completion
was broken.

Add systemd-analyze verify. Make systemctl link complete only
unit names.

shell-completion/bash/systemd-analyze

@@ -44,6 +44,7 @@ _systemd_analyze() {
                 [CRITICAL_CHAIN]='critical-chain'
                 [DOT]='dot'
                 [LOG_LEVEL]='set-log-level'
+                [VERIFY]='verify'
         )
 
         _init_completion || return
@@ -99,6 +100,14 @@ _systemd_analyze() {
                         comps='debug info notice warning err crit alert emerg'
                 fi
 
+        elif __contains_word "$verb" ${VERBS[VERIFY]}; then
+                if [[ $cur = -* ]]; then
+                        comps='--help --version --system --user --no-man'
+                else
+                        comps=$( compgen -A file -- "$cur" )
+                        compopt -o filenames
+                fi
+
         fi
 
         COMPREPLY=( $(compgen -W '$comps' -- "$cur") )