* infrun.c (struct execution_control_state): Delete field
"stepping_through_sigtramp".
(init_execution_control_state): Do not set same.
(context_switch): Do not pass same to save_infrun_state and
load_infrun_state.
* gdbthread.h (struct thread_info): Delete field
stepping_through_sigtramp.
(save_infrun_state, load_infrun_state): Delete parameter
stepping_through_sigtramp.
* thread.c (load_infrun_state, save_infrun_state): Update.