gcc: move .dll.a* outputs to $lib
gcc: move .dll.a* outputs to $lib

These are expected to be here for Windows compilation. The change in
e1831ebea3bcb415800a74fe458f802e63549e1c didn’t move these
correctly (while still patching the search paths).

https://hydra.nixos.org/build/114202790

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs