bintools-wrapper: fix inverted link32 check

[Emantor]

Motivation for this change

The new skip for the dynamic linker includes a change in behaviour,
previously the $link32 variable was checked using an arithmetic
expression via (( )). This returns zero if the output of the arithmetic
expression if nonzero, i.e. link32=1 would return zero and the if
condition would be executed.
The code refactored this to use "$link32" = "0" which is incorrect in
this case, since we want this if conditional to run if $link32 is 1.

Small shell excerpt for clarity:

$ export link32=1
$ export cookie=1
$ if [[ "$cookie" = "1" ]] && (( "$link32" )); then echo "do some stuff"; fi;
do some stuff
$ if [[ "$cookie" = "1" && "$link32" = "0" ]]; then echo "do some stuff"; fi;
$

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[FRidh]

Please refer in your commit message to the commits that change the behaviour.

[Emantor]

Please refer in your commit message to the commits that change the behaviour.

Pushed a commit which includes a reference to the commit that introduced the change.

[Atemu]

This returns zero if the output of the arithmetic expression if nonzero

Oof.

Might be worth documenting that funny little quirk in a comment; I don't think anyone who hasn't personally been bitten by this would expect that to happen.

I can confirm that wineWowPackages build again with this patch applied!

[Emantor]

This returns zero if the output of the arithmetic expression if nonzero

Oof.

Might be worth documenting that funny little quirk in a comment; I don't think anyone who hasn't personally been bitten by this would expect that to happen.

Since this quirk was removed in the previous commit, I think there is no additional documentation requirement. I think the way it's scripted now is good.