perf tools: Support for events bash completion

Add basic bash completion for the -e option in record, top and stat
subcommands. Only hardware, software and tracepoint events are
supported.

Breakpoints, raw events and events grouping completion need more
thinking.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1344522713-27951-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/bash_completion

@@ -6,7 +6,7 @@ _perf()
 	local cur cmd
 
 	COMPREPLY=()
-	_get_comp_words_by_ref cur
+	_get_comp_words_by_ref cur prev
 
 	cmd=${COMP_WORDS[0]}
 
@@ -14,6 +14,10 @@ _perf()
 	if [ $COMP_CWORD -eq 1 ]; then
 		cmds=$($cmd --list-cmds)
 		COMPREPLY=( $( compgen -W '$cmds' -- "$cur" ) )
+	# List possible events for -e option
+	elif [[ $prev == "-e" && "${COMP_WORDS[1]}" == @(record|stat|top) ]]; then
+		cmds=$($cmd list --raw-dump)
+		COMPREPLY=( $( compgen -W '$cmds' -- "$cur" ) )
 	# Fall down to list regular files
 	else
 		_filedir