It's unusable from userland - it uses elf_gregset_t, which is not
provided by exported headers. glibc has it in sys/procfs.h, but
the same file defines struct elf_prstatus, so linux/elfcore.h can't
be included once sys/procfs.h has been pulled. Same goes for uclibc
and dietlibc simply doesn't have elf_gregset_t defined anywhere.
IOW, no userland source is including that thing.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>