native_cctools: Don't use libc++ from pinned clang

Now that we include the macOS SDK libc++ headers in our macOS SDK
tarball, we no longer need this hack to use the libc++ from our pinned
clang.

depends/packages/native_cctools.mk

@@ -72,7 +72,5 @@ define $(package)_stage_cmds
   cp -P bin/clang++ $($(package)_staging_prefix_dir)/bin/ &&\
   cp lib/libLTO.so $($(package)_staging_prefix_dir)/lib/ && \
   cp -rf lib/clang/$($(package)_clang_version)/include/* $($(package)_staging_prefix_dir)/lib/clang/$($(package)_clang_version)/include/ && \
-  cp bin/llvm-dsymutil $($(package)_staging_prefix_dir)/bin/$(host)-dsymutil && \
-  if `test -d include/c++/`; then cp -rf include/c++/ $($(package)_staging_prefix_dir)/include/; fi && \
-  if `test -d lib/c++/`; then cp -rf lib/c++/ $($(package)_staging_prefix_dir)/lib/; fi
+  cp bin/llvm-dsymutil $($(package)_staging_prefix_dir)/bin/$(host)-dsymutil
 endef