[PATCH] split assume pipe2/dup3/sock_cloexec knobs

[Roland McGrath]

This looks fine to me.  

Incidentally it makes me wonder why we don't have attribute_hidden
on all such variables.  As it is, they all get GOT slots needing
startup-time R_*_RELATIVE relocs (and corresponding indirection cost
at runtime), don't they?

I wonder if there is something analogous to check-localplt that we
could come up with for global-variable GOT slots and root this out
generally.  More radically, we could conceivably one day just
compile everything with -fvisibility=hidden and specifically
annotate (via some new libc-symbol.h macro shorthand) each function
intended to be exported with an overriding attribute.  Hmm.


Thanks,
Roland