Recover the complicated situation after my bad merge

I made a mistake merge.  Reverting it in c778945806 undid the state
on master, but now I realize it crippled the git merge mechanism.
As the merge contained a mix of commits from `master..staging-next`
and other commits from `staging-next..staging`, it got the
`staging-next` branch into a state that was difficult to recover.

I reconstructed the "desired" state of staging-next tree by:
 - checking out the last commit of the problematic range: 4effe769e2
 - `git rebase -i --preserve-merges a8a018ddc0` - dropping the mistaken
   merge commit and its revert from that range (while keeping
   reapplication from 4effe769e2)
 - merging the last unaffected staging-next commit (803ca85c20)
 - fortunately no other commits have been pushed to staging-next yet
 - applying a diff on staging-next to get it into that state

pkgs/development/compilers/rust/binary.nix

@@ -1,4 +1,4 @@
-{ stdenv, makeWrapper, bash, curl, darwin
+{ stdenv, makeWrapper, bash, curl, darwin, zlib
 , version
 , src
 , platform
@@ -42,17 +42,23 @@ rec {
       ./install.sh --prefix=$out \
         --components=${installComponents}
 
-      ${optionalString (stdenv.isLinux && bootstrapping) ''
+      ${optionalString (stdenv.isLinux && bootstrapping) (''
         patchelf \
           --set-interpreter $(cat $NIX_CC/nix-support/dynamic-linker) \
           "$out/bin/rustc"
+        '' + optionalString (stdenv.lib.versionAtLeast version "1.46")
+        # rustc bootstrap needs libz starting from 1.46
+        ''
+          ln -s ${zlib}/lib/libz.so.1 $out/lib/libz.so.1
+          ln -s ${zlib}/lib/libz.so $out/lib/libz.so
+        '' + ''
         patchelf \
           --set-interpreter $(cat $NIX_CC/nix-support/dynamic-linker) \
           "$out/bin/rustdoc"
         patchelf \
           --set-interpreter $(cat $NIX_CC/nix-support/dynamic-linker) \
           "$out/bin/cargo"
-      ''}
+      '')}
 
       # Do NOT, I repeat, DO NOT use `wrapProgram` on $out/bin/rustc
       # (or similar) here. It causes strange effects where rustc loads