https://github.com/libunwind/libunwind/issues/264

From a716a18c0c2a089c55d83b067071a4cfc47e8a35 Mon Sep 17 00:00:00 2001
From: kasperk81 <83082615+kasperk81@users.noreply.github.com>
Date: Wed, 30 Jun 2021 23:23:22 +0000
Subject: [PATCH] Fix -mx32 compilation error

--- a/src/x86_64/Gos-linux.c
+++ b/src/x86_64/Gos-linux.c
@@ -149,7 +149,7 @@ x86_64_sigreturn (unw_cursor_t *cursor)
   __asm__ __volatile__ ("mov %0, %%rsp;"
                         "mov %1, %%rax;"
                         "syscall"
-                        :: "r"(sc), "i"(SYS_rt_sigreturn)
+                        :: "r"((uint64_t)sc), "i"(SYS_rt_sigreturn)
                         : "memory");
   abort();
 }