MFC r234840:

MFC r234840:
Split the symlook_obj1 into a loop iterating over the ELF object symbol
hash elements, and a helper matched_symbol() which match the given hash
entry and request, performing needed type and version checks.

MFC r234841:
Add GNU hash support for rtld.

MFC r235054:
Work around a situation where symlook_obj() could be called for the
object for which digest_dynamic1() was not done yet. Just return
EINVAL and do not try to dereference NULL buckets hash array.

git-svn-id: svn://svn.freebsd.org/base/stable/9@235396 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f