[gn build] Port 5629d49

Author: llvmgnsyncbot

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

@@ -84,6 +84,7 @@ if (current_toolchain == default_toolchain) {
       "__algorithm/copy.h",
       "__algorithm/copy_backward.h",
       "__algorithm/copy_if.h",
+      "__algorithm/copy_move_common.h",
       "__algorithm/copy_n.h",
       "__algorithm/count.h",
       "__algorithm/count_if.h",
@@ -662,6 +663,7 @@ if (current_toolchain == default_toolchain) {
       "__type_traits/is_abstract.h",
       "__type_traits/is_aggregate.h",
       "__type_traits/is_allocator.h",
+      "__type_traits/is_always_bitcastable.h",
       "__type_traits/is_arithmetic.h",
       "__type_traits/is_array.h",
       "__type_traits/is_assignable.h",