ci: fixup gn check to actually run gn check (#37680)

* ci: fixup gn check to actually run gn check

Co-authored-by: John Kleinschmidt <[email protected]>

* chore: update filenames.libcxx.gni

---------

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: John Kleinschmidt <[email protected]>

.circleci/config/base.yml

@@ -962,26 +962,13 @@ step-ts-compile: &step-ts-compile
 # List of all steps.
 steps-electron-gn-check: &steps-electron-gn-check
   steps:
-    - *step-checkout-electron
-    - *step-depot-tools-get
-    - *step-depot-tools-add-to-path
     - install-python2-mac
-    - *step-setup-env-for-build
     - *step-setup-goma-for-build
-    - *step-generate-deps-hash
-    - *step-touch-sync-done
-    - maybe-restore-portaled-src-cache
-    - run:
-        name: Ensure src checkout worked
-        command: |
-          if [ ! -d "src/third_party/blink" ]; then
-            echo src cache was not restored for an unknown reason
-            exit 1
-          fi
-    - run:
-        name: Wipe Electron
-        command: rm -rf src/electron
-    - *step-checkout-electron
+    - checkout-from-cache
+    - *step-setup-env-for-build
+    - *step-wait-for-goma
+    - *step-gn-gen-default
+    - *step-gn-check
 
 steps-electron-ts-compile-for-doc-change: &steps-electron-ts-compile-for-doc-change
   steps:

filenames.libcxx.gni

@@ -271,6 +271,10 @@ libcxx_headers = [
   "//buildtools/third_party/libc++/trunk/include/__debug",
   "//buildtools/third_party/libc++/trunk/include/__debug_utils/randomize_range.h",
   "//buildtools/third_party/libc++/trunk/include/__errc",
+  "//buildtools/third_party/libc++/trunk/include/__expected/bad_expected_access.h",
+  "//buildtools/third_party/libc++/trunk/include/__expected/expected.h",
+  "//buildtools/third_party/libc++/trunk/include/__expected/unexpect.h",
+  "//buildtools/third_party/libc++/trunk/include/__expected/unexpected.h",
   "//buildtools/third_party/libc++/trunk/include/__filesystem/copy_options.h",
   "//buildtools/third_party/libc++/trunk/include/__filesystem/directory_entry.h",
   "//buildtools/third_party/libc++/trunk/include/__filesystem/directory_iterator.h",
@@ -670,6 +674,7 @@ libcxx_headers = [
   "//buildtools/third_party/libc++/trunk/include/__type_traits/remove_reference.h",
   "//buildtools/third_party/libc++/trunk/include/__type_traits/remove_volatile.h",
   "//buildtools/third_party/libc++/trunk/include/__type_traits/result_of.h",
+  "//buildtools/third_party/libc++/trunk/include/__type_traits/strip_signature.h",
   "//buildtools/third_party/libc++/trunk/include/__type_traits/type_identity.h",
   "//buildtools/third_party/libc++/trunk/include/__type_traits/type_list.h",
   "//buildtools/third_party/libc++/trunk/include/__type_traits/underlying_type.h",
@@ -742,6 +747,7 @@ libcxx_headers = [
   "//buildtools/third_party/libc++/trunk/include/errno.h",
   "//buildtools/third_party/libc++/trunk/include/exception",
   "//buildtools/third_party/libc++/trunk/include/execution",
+  "//buildtools/third_party/libc++/trunk/include/expected",
   "//buildtools/third_party/libc++/trunk/include/experimental/__config",
   "//buildtools/third_party/libc++/trunk/include/experimental/__memory",
   "//buildtools/third_party/libc++/trunk/include/experimental/algorithm",