Unregister pthread_atfork handlers on dlclose()

Change-Id: I326fdf6bb06bed12743f08980b5c69d849c015b8
diff --git a/libc/arch-mips/bionic/crtbegin.c b/libc/arch-mips/bionic/crtbegin.c
index 50e9eeb..d72ec7b 100644
--- a/libc/arch-mips/bionic/crtbegin.c
+++ b/libc/arch-mips/bionic/crtbegin.c
@@ -92,3 +92,4 @@
 
 #include "../../arch-common/bionic/__dso_handle.h"
 #include "../../arch-common/bionic/atexit.h"
+#include "../../arch-common/bionic/pthread_atfork.h"