perf trace: Mark which syscall arguments go from user space to kernel space

perf trace: Mark which syscall arguments go from user space to kernel space

We need to know where to collect it in the BPF augmenters, if in the
sys_enter hook or in the sys_exit hook.

Start with the SCA_FILENAME one, that is just from user to kernel space.

The alternative, better, but takes a bit more time than I have now, is
to use the __user information that is already in the syscall args and
encoded in BTF via a tag, do it later.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>