libbb: introduce bb_signals and bb_signals_recursive,

which sets same handler for many signals. sig_catch is nuked
(bb_signals_recursive is more descriptive name).
*: use them as appropriate. 

function                                             old     new   delta
bb_signals_recursive                                   -      95     +95
bb_signals                                             -      52     +52
run_command                                          258     273     +15
svlogd_main                                         1368    1377      +9
runsv_main                                          1746    1752      +6
runsvdir_main                                       1643    1646      +3
UNSPEC_print                                          64      66      +2
time_main                                           1128    1127      -1
...
resize_main                                          246     210     -36
sig_catch                                             63       -     -63
set_fatal_sighandler                                  85      14     -71
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 5/24 up/down: 182/-548)        Total: -366 bytes

1 files changed, 6 insertions, 4 deletions

diff --git a/runit/runsvdir.c b/runit/runsvdir.c
index 4225ac101..3ff1d4c23 100644
--- a/runit/runsvdir.c
+++ b/runit/runsvdir.c
@@ -100,8 +100,10 @@ static void runsv(int no, const char *name)
                 /* child */
                 if (set_pgrp)
                         setsid();
-                signal(SIGHUP, SIG_DFL);
-                signal(SIGTERM, SIG_DFL);
+                bb_signals(0
+                        + (1 << SIGHUP)
+                        + (1 << SIGTERM)
+                        , SIG_DFL);
                 execvp(prog[0], prog);
                 fatal2_cannot("start runsv ", name);
         }
@@ -232,8 +234,8 @@ int runsvdir_main(int argc, char **argv)
                         bb_show_usage();
         }
 
-        sig_catch(SIGTERM, s_term);
-        sig_catch(SIGHUP, s_hangup);
+        bb_signals_recursive(1 << SIGTERM, s_term);
+        bb_signals_recursive(1 << SIGHUP, s_hangup);
         svdir = *argv++;
         if (argv && *argv) {
                 rplog = *argv;