Some programs open /proc/self/exe to read some data. Currently valgrind
supports following the /proc/self/exe link (to the original binary, so you
could then open that), but directly opening /proc/self/exe will open the
valgrind tool, not the executable file itself.
Add ML_(handle_self_exe_open) which dups VG_(cl_exec_fd) if the file
to open is /proc/self/exe or /proc/<pid>/exe. And do the same for openat.
https://bugs.kde.org/show_bug.cgi?id=140178