configure: Determine whether <link.h> is useable
configure: Determine whether <link.h> is useable

This header defines "struct link_map", which contains information of where a
library is loaded at run time, which can be used to determine the effective
load address of a shared object.

aperezdc/eris,aperezdc/lua-eol,aperezdc/eris,aperezdc/lua-eol