Expose context::CheckLintNameResult

Clippy needs it

src/librustc_lint/lib.rs

@@ -76,7 +76,7 @@ use unused::*;
 
 /// Useful for other parts of the compiler / Clippy.
 pub use builtin::SoftLints;
-pub use context::{EarlyContext, LateContext, LintContext, LintStore};
+pub use context::{CheckLintNameResult, EarlyContext, LateContext, LintContext, LintStore};
 pub use early::check_ast_crate;
 pub use late::check_crate;
 pub use passes::{EarlyLintPass, LateLintPass};