Revert "rust: use lld on pkgsStatic aarch64"

  # passed on a build=x86_64/host=aarch64 compilation.

  envVars = let

    # As a workaround for https://github.com/rust-lang/rust/issues/89626 use lld on pkgsStatic aarch64

    shouldUseLLD = platform: platform.isAarch64 && platform.isStatic && !stdenv.hostPlatform.isDarwin;

    ccForBuild = "${pkgsBuildHost.stdenv.cc}/bin/${pkgsBuildHost.stdenv.cc.targetPrefix}cc";

    cxxForBuild = "${pkgsBuildHost.stdenv.cc}/bin/${pkgsBuildHost.stdenv.cc.targetPrefix}c++";

    linkerForBuild = ccForBuild;

    ccForHost = "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc";

    cxxForHost = "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}c++";

    linkerForHost = if shouldUseLLD stdenv.targetPlatform

      && !stdenv.cc.bintools.isLLVM

      then "${pkgsBuildHost.llvmPackages.bintools}/bin/${stdenv.cc.targetPrefix}ld.lld"

      else ccForHost;

    linkerForHost = ccForHost;

    # Unfortunately we must use the dangerous `pkgsTargetTarget` here

    # because hooks are artificially phase-shifted one slot earlier

    # a targetPlatform to them).

    ccForTarget = "${pkgsTargetTarget.stdenv.cc}/bin/${pkgsTargetTarget.stdenv.cc.targetPrefix}cc";

    cxxForTarget = "${pkgsTargetTarget.stdenv.cc}/bin/${pkgsTargetTarget.stdenv.cc.targetPrefix}c++";

    linkerForTarget = if shouldUseLLD pkgsTargetTarget.stdenv.targetPlatform

      && !pkgsTargetTarget.stdenv.cc.bintools.isLLVM # whether stdenv's linker is lld already

      then "${pkgsBuildTarget.llvmPackages.bintools}/bin/${pkgsTargetTarget.stdenv.cc.targetPrefix}ld.lld"

      else ccForTarget;

    linkerForTarget = ccForTarget;

    rustBuildPlatform = stdenv.buildPlatform.rust.rustcTarget;

    rustBuildPlatformSpec = stdenv.buildPlatform.rust.rustcTargetSpec;