[gn build] Port 04760bf

Author: llvmgnsyncbot

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

@@ -168,6 +168,7 @@ if (current_toolchain == default_toolchain) {
       "__algorithm/ranges_find_first_of.h",
       "__algorithm/ranges_find_if.h",
       "__algorithm/ranges_find_if_not.h",
+      "__algorithm/ranges_find_last.h",
       "__algorithm/ranges_for_each.h",
       "__algorithm/ranges_for_each_n.h",
       "__algorithm/ranges_generate.h",