gdb: make debug_target use one-liners

Turn the debug prints in debug_target's method to be one liners.  For
instance, change this:

    gdb_printf (gdb_stdlog, "<- %s->wait (", this->beneath ()->shortname ());
    gdb_puts (target_debug_print_ptid_t (arg0), gdb_stdlog);
    gdb_puts (", ", gdb_stdlog);
    gdb_puts (target_debug_print_target_waitstatus_p (arg1), gdb_stdlog);
    gdb_puts (", ", gdb_stdlog);
    gdb_puts (target_debug_print_target_wait_flags (arg2), gdb_stdlog);
    gdb_puts (") = ", gdb_stdlog);
    target_debug_print_ptid_t (result);
    gdb_puts ("\n", gdb_stdlog);

into this:

    gdb_printf (gdb_stdlog,
               "<- %s->wait (%s, %s, %s) = %s\n",
               this->beneath ()->shortname (),
               target_debug_print_ptid_t (arg0).c_str (),
               target_debug_print_target_waitstatus_p (arg1).c_str (),
               target_debug_print_target_wait_flags (arg2).c_str (),
               target_debug_print_ptid_t (result).c_str ());

This makes it possible for a subsequent patch to turn this gdb_printf
call into a `target_debug_printf` call.

Change-Id: I808202438972fac1bba2f8ccb63e66a4fcef20c9
Approved-By: Tom Tromey <tom@tromey.com>
3 files changed