ffi: remove permission checks from dlclose and dlsym

The docs describe `ffi.dlclose(handle)` and `ffi.dlsym(handle, symbol)`
as equivalent to `handle.close()` and `handle.getSymbol(symbol)`, but
only the functions called `checkFFIPermission()`. After
`process.permission.drop('ffi')`, `ffi.dlclose(lib)` threw
`ERR_ACCESS_DENIED` while `lib.close()` succeeded.

Remove the checks so the functions defer to the handle. Permission is
already checked when the `DynamicLibrary` is constructed, and dropping
a permission does not revoke resources that are already open.

Signed-off-by: Trivikram Kamat <16024985+trivikr@users.noreply.github.com>
Assisted-by: claude:opus-5.5
PR-URL: https://github.com/nodejs/node/pull/66426
Fixes: https://github.com/nodejs/node/issues/66425
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

lib/ffi.js

@@ -252,12 +252,10 @@ function dlopen(path, definitions) {
 }
 
 function dlclose(handle) {
-  checkFFIPermission();
   handle.close();
 }
 
 function dlsym(handle, symbol) {
-  checkFFIPermission();
   return handle.getSymbol(symbol);
 }
 

test/ffi/test-ffi-permissions.js

@@ -74,7 +74,7 @@ test('permission model blocks ffi memory and helper APIs', () => {
     ffi.getCurrentEventLoop();
   }, denied);
 
-  assert.throws(() => {
-    ffi.dlclose({ close() {} });
-  }, denied);
+  // Like handle.close() and handle.getSymbol(), these do not check permissions.
+  ffi.dlclose({ close() {} });
+  assert.strictEqual(ffi.dlsym({ getSymbol: () => 1n }, 'x'), 1n);
 });