Fixes userspace compiler errors:

error: unknown type name ‘stack_t’
error: field ‘uc_mcontext’ has incomplete type
struct sigcontext uc_mcontext;
error: unknown type name ‘sigset_t’

Signed-off-by: Mikko Rapeli <redacted>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
---
 include/uapi/asm-generic/ucontext.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/uapi/asm-generic/ucontext.h b/include/uapi/asm-generic/ucontext.h
index ad77343e8a9a..448152801c4f 100644
--- a/include/uapi/asm-generic/ucontext.h
+++ b/include/uapi/asm-generic/ucontext.h

@@ -1,6 +1,9 @@
 #ifndef __ASM_GENERIC_UCONTEXT_H
 #define __ASM_GENERIC_UCONTEXT_H
 
+#include <asm/signal.h>
+#include <asm/sigcontext.h>
+
 struct ucontext {
 	unsigned long	  uc_flags;
 	struct ucontext  *uc_link;

-- 
2.13.3