Update syscall lists for Linux 5.15

Linux 5.15 has one new syscall, process_mrelease (and also enables the
clone3 syscall for RV32).  It also has a macro __NR_SYSCALL_MASK for
Arm, which is not a syscall but matches the pattern used for syscall
macro names.

Add __NR_SYSCALL_MASK to the names filtered out in the code dealing
with syscall lists, update syscall-names.list for the new syscall and
regenerate the arch-syscall.h headers with build-many-glibcs.py
update-syscalls.

Tested with build-many-glibcs.py.

sysdeps/unix/sysv/linux/sparc/sparc32/arch-syscall.h

@@ -242,6 +242,7 @@
 #define __NR_preadv2 358
 #define __NR_prlimit64 331
 #define __NR_process_madvise 440
+#define __NR_process_mrelease 448
 #define __NR_process_vm_readv 338
 #define __NR_process_vm_writev 339
 #define __NR_pselect6 297

sysdeps/unix/sysv/linux/sparc/sparc64/arch-syscall.h

@@ -222,6 +222,7 @@
 #define __NR_preadv2 358
 #define __NR_prlimit64 331
 #define __NR_process_madvise 440
+#define __NR_process_mrelease 448
 #define __NR_process_vm_readv 338
 #define __NR_process_vm_writev 339
 #define __NR_pselect6 297