use_custom_libcxx_argument_build_support.patch

diff --git a/config/BUILD.gn b/config/BUILD.gn
index 6fb49548b..dcd2643a4 100644
--- a/config/BUILD.gn
+++ b/config/BUILD.gn
@@ -240,6 +240,8 @@ group("common_deps") {
 
   if (use_custom_libcxx) {
     public_deps += [ "//buildtools/third_party/libc++" ]
+  } else {
+    public_deps += [ "//buildtools/third_party/libunwind" ]
   }
 
   if (use_afl) {