refactor: deprecate ELAST constants

This set of constants had already been discussed to cause some issues in
#3131. This patch deprecates such bu-prone and
latest-error symbols such that the interface to the `libc` crate is not
prone to SemVer-breakage as often as the values change upstream.

Author: dybucc

src/unix/bsd/apple/mod.rs

@@ -2143,6 +2143,12 @@ pub const ENOTRECOVERABLE: c_int = 104;
 pub const EOWNERDEAD: c_int = 105;
 pub const EQFULL: c_int = 106;
 pub const ENOTCAPABLE: c_int = 107;
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 107;
 
 pub const EAI_AGAIN: c_int = 2;

src/unix/bsd/freebsdlike/dragonfly/mod.rs

@@ -548,6 +548,12 @@ pub const ENOMEDIUM: c_int = 93;
 pub const ENOTRECOVERABLE: c_int = 94;
 pub const EOWNERDEAD: c_int = 95;
 pub const EASYNC: c_int = 99;
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 99;
 pub const RLIMIT_POSIXLOCKS: c_int = 11;
 #[deprecated(since = "0.2.64", note = "Not stable across OS versions")]

src/unix/bsd/freebsdlike/freebsd/freebsd11/mod.rs

@@ -258,6 +258,12 @@ s! {
     }
 }
 
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 96;
 pub const RAND_MAX: c_int = 0x7fff_fffd;
 pub const KI_NSPARE_PTR: usize = 6;

src/unix/bsd/freebsdlike/freebsd/freebsd12/mod.rs

@@ -304,6 +304,12 @@ s! {
 }
 
 pub const RAND_MAX: c_int = 0x7fff_fffd;
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 97;
 
 /// max length of devicename

src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs

@@ -317,6 +317,12 @@ s! {
 }
 
 pub const RAND_MAX: c_int = 0x7fff_ffff;
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 97;
 
 pub const KF_TYPE_EVENTFD: c_int = 13;

src/unix/bsd/freebsdlike/freebsd/freebsd14/mod.rs

@@ -319,6 +319,12 @@ s! {
 }
 
 pub const RAND_MAX: c_int = 0x7fff_ffff;
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 97;
 
 pub const KF_TYPE_EVENTFD: c_int = 13;

src/unix/bsd/freebsdlike/freebsd/freebsd15/mod.rs

@@ -321,6 +321,12 @@ s! {
 }
 
 pub const RAND_MAX: c_int = 0x7fff_ffff;
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 97;
 
 pub const KF_TYPE_EVENTFD: c_int = 13;

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

@@ -945,6 +945,12 @@ pub const EBADMSG: c_int = 92;
 pub const ENOTRECOVERABLE: c_int = 93;
 pub const EOWNERDEAD: c_int = 94;
 pub const EPROTO: c_int = 95;
+#[deprecated(
+    since = "0.2.187",
+    note = "This constant, among others often used in C for the purposes of denoting the latest \
+            value or limit in a set of constants, has been deprecated. See #3131 for details and \
+            discussion."
+)]
 pub const ELAST: c_int = 95;
 
 pub const F_DUPFD_CLOEXEC: c_int = 10;