patch 8.2.2312: build failure with Ruby 3.0 and 32 bits

Problem:    Build failure with Ruby 3.0 and 32 bits.
Solution:   Add #ifdef. (closes #7638)

Author: brammool

src/if_ruby.c

@@ -612,11 +612,13 @@ rb_check_type_stub(VALUE obj, int t)
 {
     dll_rb_check_type(obj, t);
 }
+#   if VIM_SIZEOF_INT < VIM_SIZEOF_LONG // 64 bits only
     unsigned long
 rb_num2uint_stub(VALUE x)
 {
     return dll_rb_num2uint(x);
 }
+#   endif
     void
 ruby_malloc_size_overflow_stub(size_t x, size_t y)
 {

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2312,
 /**/
     2311,
 /**/