[gn build] Port 7e1ee1e

Author: llvmgnsyncbot

llvm/utils/gn/secondary/libcxx/include/BUILD.gn

@@ -400,6 +400,7 @@ if (current_toolchain == default_toolchain) {
       "__coroutine/trivial_awaitables.h",
       "__debug",
       "__debug_utils/randomize_range.h",
+      "__debug_utils/strict_weak_ordering_check.h",
       "__exception/exception.h",
       "__exception/exception_ptr.h",
       "__exception/nested_exception.h",