libc: wipe out all references from copied libgcc_s.so.1

Without the change a copy from freshly built `gcc` still retains a
reference even after `patchelf --remove-rpath` because `patchelf` does
not cleanup dynamic sprintgs section.

The change stubs the reference out and fixes build on bootstraps where
`gcc` is built before `glibc`.

pkgs/development/libraries/glibc/default.nix

@@ -86,6 +86,9 @@ in
           # rely on default RUNPATHs of the binary and other libraries
           # Do no force-pull wrong glibc.
           patchelf --remove-rpath $out/lib/libgcc_s.so.1
+          # 'patchelf' does not remove the string itself. Wipe out
+          # string reference to avoid possible link to bootstrapTools
+          ${buildPackages.nukeReferences}/bin/nuke-refs $out/lib/libgcc_s.so.1
       fi
     '';