Remove some mask constants from FreeBSD

These are bitmasks that are intended to be used within the kernel.  New
features may widen them, so their values aren't stable.  They probably
don't have any legitimate uses in userland.  And their values have
changed in FreeBSD 15, which is causing CI failures.

freebsd/freebsd-src@eea3e4d
freebsd/freebsd-src@851dc7f

(backport <#4691>)
(cherry picked from commit fbfa292)

Author: asomers

libc-test/semver/freebsd-x86_64.txt

@@ -1,7 +1,6 @@
 Elf64_Auxinfo
 KINFO_FILE_SIZE
 MAP_32BIT
-_MC_FLAG_MASK
 _MC_FPFMT_NODEV
 _MC_FPFMT_XMM
 _MC_FPOWNED_FPU

libc-test/semver/freebsd.txt

@@ -683,8 +683,6 @@ JAIL_API_VERSION
 JAIL_ATTACH
 JAIL_CREATE
 JAIL_DYING
-JAIL_GET_MASK
-JAIL_SET_MASK
 JAIL_SYS_DISABLE
 JAIL_SYS_INHERIT
 JAIL_SYS_NEW

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

@@ -2950,8 +2950,6 @@ pub const JAIL_CREATE: c_int = 0x01;
 pub const JAIL_UPDATE: c_int = 0x02;
 pub const JAIL_ATTACH: c_int = 0x04;
 pub const JAIL_DYING: c_int = 0x08;
-pub const JAIL_SET_MASK: c_int = 0x0f;
-pub const JAIL_GET_MASK: c_int = 0x08;
 pub const JAIL_SYS_DISABLE: c_int = 0;
 pub const JAIL_SYS_NEW: c_int = 1;
 pub const JAIL_SYS_INHERIT: c_int = 2;

src/unix/bsd/freebsdlike/freebsd/x86_64/mod.rs

@@ -334,7 +334,6 @@ pub const MINSIGSTKSZ: size_t = 2048; // 512 * 4
 pub const _MC_HASSEGS: u32 = 0x1;
 pub const _MC_HASBASES: u32 = 0x2;
 pub const _MC_HASFPXSTATE: u32 = 0x4;
-pub const _MC_FLAG_MASK: u32 = _MC_HASSEGS | _MC_HASBASES | _MC_HASFPXSTATE;
 
 pub const _MC_FPFMT_NODEV: c_long = 0x10000;
 pub const _MC_FPFMT_XMM: c_long = 0x10002;