This is xnu-8019. See this file in:
################################################################################
#
# File format is:
#
#  # comments
#  %{
#  < verbatim directives >
#  %}
#  func1
#  func2
#  ...
#  funcn
#
# Emtpy lines are ignored
#
################################################################################

# tvOS & watchOS prohibited APIs
%{
__TVOS_PROHIBITED __WATCHOS_PROHIBITED
%}
thread_terminate
act_get_state
act_set_state
thread_depress_abort
thread_get_special_port
thread_set_special_port
thread_set_exception_ports
thread_get_exception_ports
thread_swap_exception_ports
thread_get_mach_voucher
thread_set_mach_voucher
thread_swap_mach_voucher
mach_ports_register
mach_ports_lookup
task_suspend
task_resume
task_set_info
task_get_special_port
task_set_special_port
thread_create
thread_create_running
task_set_exception_ports
task_get_exception_ports
task_swap_exception_ports
task_policy_set
task_policy_get
task_zone_info
task_get_state
task_set_state
task_set_phys_footprint_limit
task_suspend2
task_resume2
task_get_mach_voucher
task_set_mach_voucher
task_swap_mach_voucher
task_set_port_space
host_request_notification
host_info
task_wire
mach_port_allocate_name
host_create_mach_voucher
host_register_mach_voucher_attr_manager
host_register_well_known_mach_voucher_attr_manager
host_set_atm_diagnostic_flag
host_get_atm_diagnostic_flag

# watchOS prohibited APIs
%{
__WATCHOS_PROHIBITED
%}
thread_get_state
thread_set_state
thread_suspend
thread_resume
thread_abort
thread_abort_safely

# mach_port_destroy() deprecation
%{
__API_DEPRECATED("Inherently unsafe API: instead manage rights with "
    "mach_port_destruct(), mach_port_deallocate() or mach_port_mod_refs()",
    macos(10.0, 12.0), ios(2.0, 15.0), tvos(9.0, 15.0), watchos(2.0, 8.0))
%}
mach_port_destroy