Revert "Set SA_RESTORER in sigaction()"

This reverts commit e4fa46e75cd0d433b5c6c064720ed7e195cba7c8.
diff --git a/libc/arch-arm/bionic/__sig_restorer.S b/libc/arch-arm/bionic/__sig_restorer.S
deleted file mode 100644
index 3f6f284..0000000
--- a/libc/arch-arm/bionic/__sig_restorer.S
+++ /dev/null
@@ -1,7 +0,0 @@
-.global __sig_restorer
-
-/* This is the opcode sequence GDB looks for in order to recognize
-   this stack frame as a signal trampoline (see sigaction.c) */
-__sig_restorer:
-    mov r7, #119 /* __NR_sigreturn */
-    swi #0
diff --git a/libc/arch-arm/bionic/sigaction.c b/libc/arch-arm/bionic/sigaction.c
deleted file mode 100644
index 96ca7c6..0000000
--- a/libc/arch-arm/bionic/sigaction.c
+++ /dev/null
@@ -1,29 +0,0 @@
-#include <signal.h>
-
-extern int __sigaction(int signum, const struct sigaction *act, struct sigaction *oldact);
-extern void __sig_restorer();
-
-int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
-{
-    struct sigaction real_act;
-
-    /* If the caller has not set a custom restorer, then set up a default one.
-     * The code will function properly without this, however GDB will not be
-     * able to recognize the stack frame as a signal trampoline, because it
-     * is hardcoded to look for the instruction sequence that glibc uses in
-     * its custom restorer.  By creating our own restorer with the same
-     * sequence, we ensure that GDB correctly identifies this as a signal
-     * trampoline frame.
-     *
-     * See http://sourceware.org/ml/gdb/2010-01/msg00143.html for more
-     * information on this.*/
-    if(act && !(act->sa_flags & SA_RESTORER)) {
-        real_act = *act;
-        real_act.sa_flags |= SA_RESTORER;
-        real_act.sa_restorer = __sig_restorer;
-
-        act = &real_act;
-    }
-
-    return __sigaction(signum, act, oldact);
-}
diff --git a/libc/arch-arm/syscalls.mk b/libc/arch-arm/syscalls.mk
index 8afe099..c466166 100644
--- a/libc/arch-arm/syscalls.mk
+++ b/libc/arch-arm/syscalls.mk
@@ -121,13 +121,13 @@
 syscall_src += arch-arm/syscalls/__timer_getoverrun.S
 syscall_src += arch-arm/syscalls/__timer_delete.S
 syscall_src += arch-arm/syscalls/utimes.S
+syscall_src += arch-arm/syscalls/sigaction.S
 syscall_src += arch-arm/syscalls/sigprocmask.S
 syscall_src += arch-arm/syscalls/__sigsuspend.S
 syscall_src += arch-arm/syscalls/__rt_sigaction.S
 syscall_src += arch-arm/syscalls/__rt_sigprocmask.S
 syscall_src += arch-arm/syscalls/__rt_sigtimedwait.S
 syscall_src += arch-arm/syscalls/sigpending.S
-syscall_src += arch-arm/syscalls/__sigaction.S
 syscall_src += arch-arm/syscalls/socket.S
 syscall_src += arch-arm/syscalls/socketpair.S
 syscall_src += arch-arm/syscalls/bind.S
diff --git a/libc/arch-arm/syscalls/__sigaction.S b/libc/arch-arm/syscalls/sigaction.S
similarity index 81%
rename from libc/arch-arm/syscalls/__sigaction.S
rename to libc/arch-arm/syscalls/sigaction.S
index aba44b8..2696f1e 100644
--- a/libc/arch-arm/syscalls/__sigaction.S
+++ b/libc/arch-arm/syscalls/sigaction.S
@@ -2,12 +2,12 @@
 #include <sys/linux-syscalls.h>
 
     .text
-    .type __sigaction, #function
-    .globl __sigaction
+    .type sigaction, #function
+    .globl sigaction
     .align 4
     .fnstart
 
-__sigaction:
+sigaction:
     .save   {r4, r7}
     stmfd   sp!, {r4, r7}
     ldr     r7, =__NR_sigaction