clippy_lints doesn't build on rust 1.21.0-nightly (13d94d5fa

    Updating registry `https://github.com/rust-lang/crates.io-index`
  Installing clippy v0.0.150
   Compiling unicode-xid v0.0.4
   Compiling quote v0.3.15
   Compiling quine-mc_cluskey v0.2.4
   Compiling either v1.1.0
   Compiling num-traits v0.1.40
   Compiling matches v0.1.6
   Compiling getopts v0.2.14
   Compiling dtoa v0.4.1
   Compiling bitflags v0.9.1
   Compiling regex-syntax v0.4.1
   Compiling serde v1.0.11
   Compiling lazy_static v0.2.8
   Compiling itoa v0.3.1
   Compiling semver-parser v0.7.0
   Compiling unicode-normalization v0.1.5
   Compiling pulldown-cmark v0.0.15
   Compiling synom v0.11.3
   Compiling itertools v0.6.1
   Compiling semver v0.6.0
   Compiling syn v0.11.11
   Compiling serde_json v1.0.2
   Compiling toml v0.4.4
   Compiling serde_derive_internals v0.15.1
   Compiling serde_derive v1.0.11
   Compiling cargo_metadata v0.2.3
   Compiling clippy_lints v0.0.150
error[E0599]: no method named `current_level` found for type `&T` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/utils/mod.rs:549:11
    |
549 |     if cx.current_level(lint) != Level::Allow {
    |           ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&'a T` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/utils/mod.rs:562:11
    |
562 |     if cx.current_level(lint) != Level::Allow {
    |           ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&'a T` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/utils/mod.rs:577:11
    |
577 |     if cx.current_level(lint) != Level::Allow {
    |           ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&'a T` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/utils/mod.rs:597:11
    |
597 |     if cx.current_level(lint) != Level::Allow {
    |           ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&rustc::lint::LateContext<'_, '_>` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/cyclomatic_complexity.rs:197:11
    |
197 |     if cx.current_level(CYCLOMATIC_COMPLEXITY) != Level::Allow {
    |           ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&rustc::lint::LateContext<'_, '_>` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/matches.rs:197:39
    |
197 |         if ty.sty != ty::TyBool || cx.current_level(MATCH_BOOL) == Allow {
    |                                       ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&rustc::lint::LateContext<'a, 'tcx>` in the current scope
  --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/strings.rs:86:35
   |
86 |                 if let Allow = cx.current_level(STRING_ADD_ASSIGN) {
   |                                   ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&rustc::lint::LateContext<'_, '_>` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/unicode.rs:118:23
    |
118 |                 if cx.current_level(UNICODE_NOT_NFC) == Level::Allow {
    |                       ^^^^^^^^^^^^^

error[E0599]: no method named `current_level` found for type `&rustc::lint::LateContext<'_, '_>` in the current scope
   --> .cargo/registry/src/github.com-1ecc6299db9ec823/clippy_lints-0.0.150/src/unicode.rs:126:11
    |
126 |     if cx.current_level(NON_ASCII_LITERAL) == Level::Allow && string.chars().zip(string.nfc()).any(|(a, b)| a != b) {
    |           ^^^^^^^^^^^^^

error: aborting due to 9 previous errors

error: Could not compile `clippy_lints`.
warning: build failed, waiting for other jobs to finish...
error: failed to compile `clippy v0.0.150`, intermediate artifacts can be found at `/tmp/cargo-install.weKiWWNQ3g5u`

Caused by:
  build failed