Switch sigpending over to rt_sigpending.

Change-Id: I7b28984796b5fb343cfbcc47e0afc3a84293d417
diff --git a/libc/arch-mips/syscalls/__rt_sigpending.S b/libc/arch-mips/syscalls/__rt_sigpending.S
new file mode 100644
index 0000000..bd4a96e
--- /dev/null
+++ b/libc/arch-mips/syscalls/__rt_sigpending.S
@@ -0,0 +1,22 @@
+/* autogenerated by gensyscalls.py */
+#include <asm/unistd.h>
+    .text
+    .globl __rt_sigpending
+    .align 4
+    .ent __rt_sigpending
+
+__rt_sigpending:
+    .set noreorder
+    .cpload $t9
+    li $v0, __NR_rt_sigpending
+    syscall
+    bnez $a3, 1f
+    move $a0, $v0
+    j $ra
+    nop
+1:
+    la $t9,__set_errno
+    j $t9
+    nop
+    .set reorder
+    .end __rt_sigpending