[gn build] port 77116bd

Author: nico

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

@@ -320,6 +320,7 @@ if (current_toolchain == default_toolchain) {
       "__chrono/convert_to_tm.h",
       "__chrono/day.h",
       "__chrono/duration.h",
+      "__chrono/exception.h",
       "__chrono/file_clock.h",
       "__chrono/formatter.h",
       "__chrono/hh_mm_ss.h",

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

@@ -320,6 +320,9 @@ if (libcxx_enable_experimental) {
         "include/tzdb/types_private.h",
         "include/tzdb/tzdb_list_private.h",
         "include/tzdb/tzdb_private.h",
+        # TODO TZDB The exception could be moved in chrono once the TZDB library
+        # is no longer experimental.
+        "chrono_exception.cpp",
         "time_zone.cpp",
         "tzdb.cpp",
         "tzdb_list.cpp",