https://github.com/python-greenlet/greenlet/commit/3be53248cd1f8e4859563b84b04054de7a9fcad2
https://github.com/python-greenlet/greenlet/commit/86c4e2a98f1bd27eff38edd5dba8c10300bc8e64

From 3be53248cd1f8e4859563b84b04054de7a9fcad2 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Mon, 16 Jan 2023 21:37:26 -0800
Subject: [PATCH] greenlet: Drop using 'register' storage class keyword

This has been dropped in c++17 and newer

Signed-off-by: Khem Raj <raj.khem@gmail.com>
--- a/src/greenlet/platform/switch_riscv_unix.h
+++ b/src/greenlet/platform/switch_riscv_unix.h
@@ -11,8 +11,8 @@
 static int
 slp_switch(void)
 {
-  register int ret;
-  register long *stackref, stsizediff;
+  int ret;
+  long *stackref, stsizediff;
   __asm__ volatile ("" : : : REGS_TO_SAVE);
   __asm__ volatile ("mv %0, sp" : "=r" (stackref) : );
   {

From 86c4e2a98f1bd27eff38edd5dba8c10300bc8e64 Mon Sep 17 00:00:00 2001
From: Jason Madden <jamadden@gmail.com>
Date: Thu, 26 Jan 2023 12:58:46 -0600
Subject: [PATCH] Add the rebind member to the allocator.

Based on, and fixes #335
--- a/src/greenlet/greenlet_allocator.hpp
+++ b/src/greenlet/greenlet_allocator.hpp
@@ -51,6 +51,11 @@ namespace greenlet
             else
                 PyMem_Free(p);
         }
+        // This member is deprecated in C++17 and removed in C++20
+        template< class U >
+        struct rebind {
+            typedef PythonAllocator<U> other;
+        };
 
     };
 }