CMakeLists.txt: update index for new files;

Author: kristopher tate

CMakeLists.txt

@@ -466,6 +466,9 @@ set(ZIG_STD_FILES
     "event/lock.zig"
     "event/locked.zig"
     "event/loop.zig"
+    "event/loop/darwin.zig"
+    "event/loop/linux.zig"
+    "event/loop/windows.zig"
     "event/rwlock.zig"
     "event/rwlocked.zig"
     "event/tcp.zig"