[gn build] Port 80525df

Author: llvmgnsyncbot

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

@@ -226,6 +226,9 @@ copy("Headers") {
     "llvm_libc_wrappers/stdlib.h",
     "llvm_libc_wrappers/string.h",
     "llvm_libc_wrappers/time.h",
+    "llvm_offload_wrappers/__llvm_offload.h",
+    "llvm_offload_wrappers/__llvm_offload_device.h",
+    "llvm_offload_wrappers/__llvm_offload_host.h",
     "lsxintrin.h",
     "lwpintrin.h",
     "lzcntintrin.h",