Auto merge of #2447 - devnexen:obsd_skip_few_consts, r=Amanieu

openbsd omit few consts check as openbsd supports release N and N-1 f…

…or a while

Author: bors

libc-test/build.rs

@@ -481,6 +481,8 @@ fn test_openbsd(target: &str) {
         match name {
             // Removed in OpenBSD 6.0
             "KERN_USERMOUNT" | "KERN_ARND" => true,
+            // Good chance it's going to be wrong depending on the host release
+            "KERN_MAXID" | "NET_RT_MAXID" => true,
             _ => false,
         }
     });