rustc: 1.33.0 -> 1.34.0

[ivan]

Motivation for this change

https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1340-2019-04-11

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• 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 nix-review --run "nix-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)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

[Mic92]

Successfully compiled fd on x86_64-linux and aarch64-linux

[Mic92]

ping @alyssais or @grahamc for macOS (nix-review pr -p fd 59366)

[alyssais]

output '/nix/store/jla837w8gwpf6aiy56ippajblmh7xkip-stdenv-darwin' is not allowed to refer to the following paths:
  /nix/store/2v7gipzb3m8fbk5ai13kj8vyqds56m48-gnum4-1.4.18
  /nix/store/jpn9q1j0wxr8nkq2k28k1qvc5smb6hbn-bison-3.3.2

[alyssais]

Although I can't say I understand how stdenv could be affected…

[Mic92]

Mhm. I would say staging is borked then.

[symphorien]

It looks like #59450

[Mic92]

Cool. @alyssais could you try again?

[alyssais]

Had to cherry-pick the fix, but after that it worked. LGTM.

[timokau]

This PR broke rustfmt again (we should probably make a list of packages that are tightly integrated with the compiler):

   Compiling version_check v0.1.5
   Compiling rustc-ap-graphviz v306.0.0
error[E0277]: the trait bound `std::borrow::Cow<'_, str>: std::convert::From<core::str::EscapeDefault<'_>>` is not satisfied
   --> /build/rustfmt-1.0.1-vendor/rustc-ap-graphviz/lib.rs:551:44
    |
551 |                     (&*s).escape_default().into()
    |                                            ^^^^ the trait `std::convert::From<core::str::EscapeDefault<'_>>` is not implement>
    |
    = help: the following implementations were found:
              <std::borrow::Cow<'a, [T]> as std::convert::From<&'a [T]>>
              <std::borrow::Cow<'a, [T]> as std::convert::From<&'a std::vec::Vec<T>>>
              <std::borrow::Cow<'a, [T]> as std::convert::From<std::vec::Vec<T>>>
              <std::borrow::Cow<'a, std::ffi::CStr> as std::convert::From<&'a std::ffi::CStr>>
            and 11 others
    = note: required because of the requirements on the impl of `std::convert::Into<std::borrow::Cow<'_, str>>` for `core::str::Esc>

error: aborting due to previous error

[timokau]

#60085