NetBSD: Replace REG_ENOSYS with REG_ILLSEQ

Upstream commit: NetBSD/src@cc8bab3

(backport <#4782>)
(cherry picked from commit b038f17)

Author: tgross35

libc-test/semver/netbsd.txt

@@ -884,7 +884,6 @@ REG_ECOLLATE
 REG_ECTYPE
 REG_EESCAPE
 REG_EMPTY
-REG_ENOSYS
 REG_EPAREN
 REG_ERANGE
 REG_ESPACE

src/unix/bsd/netbsdlike/netbsd/mod.rs

@@ -1882,7 +1882,7 @@ pub const FIBMAP: c_ulong = 0xc008667a;
 
 pub const SIGSTKSZ: size_t = 40960;
 
-pub const REG_ENOSYS: c_int = 17;
+pub const REG_ILLSEQ: c_int = 17;
 
 pub const PT_DUMPCORE: c_int = 12;
 pub const PT_LWPINFO: c_int = 13;