dl{open,error}

[Golubev I. N.]

platform: i386-pc-sco3.2v5.0.2
libtool versions: 1.3.5, 1.4

In libc of this system there no `dl{open,error}' symbols.  System
<dlfcn.h> ensures creating references to correct names by `#define
dl{open,error}'.  To ensure enabling use of dlopen in ltdl,
`configure' should use AC_TRY_LINK([#include<dlfcn.h>],...) beside
`AC_CHECK_FUNC'.  If there are no known system where `dlopen' is
present but `AC_TRY_COMPILE([#include<dlfcn.h>],...)' fails (some
additional headers needed ...), AC_TRY_LINK alone will be enough.