* dlfcn.cc (check_access): Eliminate.

(check_path_access): Use passed in path_conv buf.
(get_full_path_of_dll): Use passed in name buf to avoid a static.  Rip out most
of the path checking since LoadLibrary will do all of this automatically.
(dlopen): Set errno when appropriate (may not be compliant?).
* environ.cc (posify): Don't pass in "native" path if it seems to actually be
posix.

winsup/cygwin/environ.cc

@@ -137,7 +137,7 @@ posify (char **here, const char *value)
   char *outenv = (char *) malloc (1 + len + conv->posix_len (value));
   memcpy (outenv, src, len);
   conv->toposix (value, outenv + len);
-  conv->add_cache (outenv + len, value);
+  conv->add_cache (outenv + len, *value != '/' ? value : NULL);
 
   debug_printf ("env var converted to %s", outenv);
   *here = outenv;