[gn build] Port 7f2bcd9

Author: llvmgnsyncbot

llvm/utils/gn/secondary/clang/lib/Headers/BUILD.gn

@@ -205,6 +205,7 @@ copy("Headers") {
     "cmpccxaddintrin.h",
     "cpuid.h",
     "crc32intrin.h",
+    "cuda_wrappers/__utility/declval.h",
     "cuda_wrappers/algorithm",
     "cuda_wrappers/bits/basic_string.h",
     "cuda_wrappers/bits/shared_ptr_base.h",