new helpers: {clear,test,test_and_clear}_restore_sigmask()

helpers parallel to set_restore_sigmask(), used in the next commits

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index 0c04ffc..a109157 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -189,6 +189,23 @@
 	struct thread_info *ti = current_thread_info();
 	return ti->flags >> TI_FLAG_FAULT_CODE_SHIFT;
 }
+
+static inline void clear_restore_sigmask(void)
+{
+	current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+}
+static inline bool test_restore_sigmask(void)
+{
+	return current_thread_info()->status & TS_RESTORE_SIGMASK;
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+	struct thread_info *ti = current_thread_info();
+	if (!(ti->status & TS_RESTORE_SIGMASK))
+		return false;
+	ti->status &= ~TS_RESTORE_SIGMASK;
+	return true;
+}
 #endif	/* !__ASSEMBLY__ */
 
 #endif /* __KERNEL__ */