[gn build] Port 8a21d59

Author: llvmgnsyncbot

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

@@ -340,6 +340,7 @@ if (current_toolchain == default_toolchain) {
       "__chrono/high_resolution_clock.h",
       "__chrono/leap_second.h",
       "__chrono/literals.h",
+      "__chrono/local_info.h",
       "__chrono/month.h",
       "__chrono/month_weekday.h",
       "__chrono/monthday.h",