Constify target_pass_signals and target_program_signals
This constifies the final parameter to target_pass_signals and target_program_signals and updates the rest of gdb. Note that I have no way to test the nto-procfs.c change. gdb/ChangeLog 2019-01-14 Tom Tromey <email@example.com> * target-debug.h (target_debug_print_signals): Constify. * nto-procfs.c (nto_procfs_target::pass_signals): Update. * procfs.c (procfs_target::pass_signals): Update. * linux-nat.c (linux_nat_target::pass_signals): Update. * linux-nat.h (class linux_nat_target) <pass_signals>: Update. * target-delegates.c: Rebuild. * remote.c (remote_target::program_signals): Update. (remote_target::pass_signals): Update. * target.c (target_pass_signals): Constify argument. (target_program_signals): Likewise. * target.h (struct target_ops) <pass_signals, program_signals>: Constify argument. (target_pass_signals, target_program_signals): Constify argument.