Auto merge of #2395 - uweigand:s390x-MAP_SYNC, r=Amanieu

Add missing MAP_SYNC for s390x

Add missing constant that is causing a build error in rsix.

Author: bors

libc-test/semver/linux-s390x.txt

@@ -17,6 +17,7 @@ KEYCTL_CAPS1_NS_KEYRING_NAME
 KEYCTL_CAPS1_NS_KEY_TAG
 KEYCTL_MOVE
 MADV_SOFT_OFFLINE
+MAP_SYNC
 NFT_MSG_DELOBJ
 NFT_MSG_GETOBJ
 NFT_MSG_GETOBJ_RESET

src/unix/linux_like/linux/gnu/b64/s390x.rs

@@ -385,6 +385,7 @@ pub const MAP_POPULATE: ::c_int = 0x08000;
 pub const MAP_NONBLOCK: ::c_int = 0x010000;
 pub const MAP_STACK: ::c_int = 0x020000;
 pub const MAP_HUGETLB: ::c_int = 0x040000;
+pub const MAP_SYNC: ::c_int = 0x080000;
 
 pub const EDEADLOCK: ::c_int = 35;
 pub const ENAMETOOLONG: ::c_int = 36;