Move setjmp cookie to a shared globals struct.

Change-Id: I59a4c187d61524c4e48655c4c6376dba0d41eee2
diff --git a/libc/private/bionic_globals.h b/libc/private/bionic_globals.h
index 788a759..644b5a4 100644
--- a/libc/private/bionic_globals.h
+++ b/libc/private/bionic_globals.h
@@ -34,6 +34,7 @@
 
 struct libc_globals {
   vdso_entry vdso[VDSO_END];
+  long setjmp_cookie;
 };
 
 __LIBC_HIDDEN__ extern WriteProtected<libc_globals> __libc_globals;
@@ -41,5 +42,7 @@
 class KernelArgumentBlock;
 __LIBC_HIDDEN__ void __libc_init_vdso(libc_globals* globals,
                                       KernelArgumentBlock& args);
+__LIBC_HIDDEN__ void __libc_init_setjmp_cookie(libc_globals* globals,
+                                               KernelArgumentBlock& args);
 
 #endif