fs: revert "change statSync to accessSync..."

This reverts commit 809bf5e
("change statSync to accessSync in realpathSync").

It was causing tests to fail on Windows CI.

Ref: nodejs#4575
PR-URL: nodejs#4679
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

lib/fs.js

@@ -1550,7 +1550,7 @@ fs.realpathSync = function realpathSync(p, cache) {
         }
       }
       if (linkTarget === null) {
-        fs.accessSync(base, fs.F_OK);  // Throws ELOOP on cyclic links.
+        fs.statSync(base);
         linkTarget = fs.readlinkSync(base);
       }
       resolvedLink = pathModule.resolve(previous, linkTarget);