libstdc++.so.6 not stripped

In tor-browser-build/projects/tor/build, libstdc++.so.6 is copied from GCC to the output:

  # We need to copy the libstdc++.so.6 for Tor Browser on older Linux distros.
  # Copying it into /Browser, which feels more natural, and amending
  # LD_LIBRARY_PATH breaks updates from a Tor Browser with the old
  # LD_LIBRARY_PATH value to the Tor Browser with the newer one. Thus, we copy
  # the libstdc++ into the directory with the libs tor depends on, too. See bug
  # 13359 for further details.
  mkdir -p "$distdir/Tor/libstdc++"
  cp /var/tmp/dist/gcc/[% c("var/libdir") %]/libstdc++.so.6 "$distdir/Tor/libstdc++/"
  [% IF c("var/asan") -%]
    cp /var/tmp/dist/gcc/[% c("var/libdir") %]/libasan.so.5 "$distdir/Tor/"
    cp /var/tmp/dist/gcc/[% c("var/libdir") %]/libubsan.so.1 "$distdir/Tor/"
  [% END -%]
  chmod 700 "$distdir"/Tor/*.so*
  chmod 700 "$distdir"/Tor/libstdc++/*.so*

This file is unstripped and contains debug info. Stripping it takes it from 17 MB to 2 MB, without any impact on functionality as far as I can tell. After compression, the entire tarball is 3MB smaller.

This should be a one-line change, provided strip is deterministic. I haven't looked into it.