valgrind: look tool names from lib/*-linux-gnu dirs too

Fixes lookup on Debian 10.

Author: scop

completions/valgrind

@@ -32,7 +32,8 @@ _valgrind()
             # Tools seem to be named e.g. like memcheck-amd64-linux from which
             # we want to grab memcheck.
             COMPREPLY=( $(compgen -W '$(
-                for f in /usr{,/local}/lib{,64,exec}/valgrind/*; do
+                for f in /usr{,/local}/lib{,64,exec}{/*-linux-gnu,}/valgrind/*
+                do
                     [[ $f != *.so && -x $f && $f =~ ^.*/(.*)-[^-]+-[^-]+ ]] &&
                         printf "%s\n" "${BASH_REMATCH[1]}"
                 done)' -- "$cur") )