stapbpf PR22330 fixes :: identify format types of pe_unknown arguments

stapbpf PR22330 fixes :: identify format types of pe_unknown arguments

* bpf-translate.cxx (bpf_unparser::emit_print_format): take tok for diagnostics,
extract non-literal printf components and pass them to printf_arg_type;
signal an error if the number of printf components doesnt' match the number of args.
(printf_arg_type): take format_component argument and use it to infer the
format type in the case of pe_unknown arguments.
(bpf_unparser::emit_transport_msg): pick format_type based on perf_event_type,
which was inferred from the format string in the case of pe_unknown arguments.
(bpf_unparser::visit_embeddedcode): pass tok to emit_print_format.
(bpf_unparser::visit_print_format): remove some old TODOs, pass tok to emit_print_format.