fs: fix when path is buffer

lib/internal/fs/utils.js

@@ -336,6 +336,7 @@ function preprocessSymlinkDestination(path, type, linkPath) {
     // No preprocessing is needed on Unix.
     return path;
   }
+  path = '' + path;
   if (type === 'junction') {
     // Junctions paths need to be absolute and \\?\-prefixed.
     // A relative target is relative to the link's parent directory.
@@ -347,7 +348,7 @@ function preprocessSymlinkDestination(path, type, linkPath) {
     return pathModule.toNamespacedPath(path);
   }
   // Windows symlinks don't tolerate forward slashes.
-  return ('' + path).replace(/\//g, '\\');
+  return path.replace(/\//g, '\\');
 }
 
 // Constructor for file stats.

test/parallel/test-fs-symlink.js

@@ -56,6 +56,10 @@ fs.symlink(linkData, linkPath, common.mustCall(function(err) {
     assert.ifError(err);
     assert.strictEqual(destination, linkData);
   }));
+
+  tmpdir.refresh();
+  // Fixes: https://github.com/nodejs/node/issues/34514
+  fs.symlinkSync(Buffer.from(linkData), linkPath);
 }));
 
 // Test invalid symlink