Move all the short <signal.h> functions together.

Bug: N/A
Test: ran tests
Change-Id: Ie5509e4108efcd5d403227ce99bef2b61c79f757
diff --git a/libc/Android.bp b/libc/Android.bp
index a8c518d..2ea8514 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -10,9 +10,6 @@
     "bionic/pututline.c",
     "bionic/sched_cpualloc.c",
     "bionic/sched_cpucount.c",
-    "bionic/sigblock.c",
-    "bionic/siginterrupt.c",
-    "bionic/sigsetmask.c",
     "stdio/fmemopen.cpp",
     "stdio/parsefloat.c",
     "stdio/refill.c",
@@ -1336,25 +1333,7 @@
         "bionic/seteuid.cpp",
         "bionic/setpgrp.cpp",
         "bionic/sigaction.cpp",
-        "bionic/sigaddset.cpp",
-        "bionic/sigdelset.cpp",
-        "bionic/sigemptyset.cpp",
-        "bionic/sigfillset.cpp",
-        "bionic/sighold.cpp",
-        "bionic/sigignore.cpp",
-        "bionic/sigismember.cpp",
         "bionic/signal.cpp",
-        "bionic/signalfd.cpp",
-        "bionic/sigpause.cpp",
-        "bionic/sigpending.cpp",
-        "bionic/sigprocmask.cpp",
-        "bionic/sigqueue.cpp",
-        "bionic/sigrelse.cpp",
-        "bionic/sigset.cpp",
-        "bionic/sigsuspend.cpp",
-        "bionic/sigtimedwait.cpp",
-        "bionic/sigwait.cpp",
-        "bionic/sigwaitinfo.cpp",
         "bionic/socket.cpp",
         "bionic/spawn.cpp",
         "bionic/stat.cpp",
@@ -1375,6 +1354,7 @@
         "bionic/sys_sem.cpp",
         "bionic/sys_shm.cpp",
         "bionic/sys_siglist.c",
+        "bionic/sys_signalfd.cpp",
         "bionic/sys_signame.c",
         "bionic/sys_time.cpp",
         "bionic/sysinfo.cpp",