SDL: RISCOS: attempt to fix compilation ERANGE

From df0d696a620bf0bcf946c680ec43f31ee02136cb Mon Sep 17 00:00:00 2001
From: Sylvain <[EMAIL REDACTED]>
Date: Wed, 2 Feb 2022 15:22:14 +0100
Subject: [PATCH] RISCOS: attempt to fix compilation ERANGE

---
 src/thread/pthread/SDL_systhread.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/thread/pthread/SDL_systhread.c b/src/thread/pthread/SDL_systhread.c
index 473c710a87d..75a03abe4ab 100644
--- a/src/thread/pthread/SDL_systhread.c
+++ b/src/thread/pthread/SDL_systhread.c
@@ -41,6 +41,10 @@
 #include "../../core/linux/SDL_dbus.h"
 #endif /* __LINUX__ */
 
+#if __RISCOS__
+#  include <errno.h>
+#endif
+
 #if (defined(__LINUX__) || defined(__MACOSX__) || defined(__IPHONEOS__)) && defined(HAVE_DLOPEN)
 #include <dlfcn.h>
 #ifndef RTLD_DEFAULT