Comment by anshargal

I had to add

  #define _GNU_SOURCE
  #include <sys/mman.h>
  #include <unistd.h>

I've tested in Fabrice Bellard JSLinux with tcc (x86 arch) and on https://replit.com/languages/c (x64). I failed to see any side effect at all. gdb "catch syscall" doesn't show anything interesting too. Looks like TINY_ELF_PROGRAM is not doing anything.