Convert redundant_clone to an analysis pass

Author: Jarcho

clippy_lints/src/lib.rs

@@ -1,6 +1,7 @@
 #![feature(array_windows)]
 #![feature(binary_heap_into_iter_sorted)]
 #![feature(box_patterns)]
+#![feature(hash_extract_if)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
@@ -36,6 +37,7 @@ extern crate rustc_infer;
 extern crate rustc_lexer;
 extern crate rustc_lint;
 extern crate rustc_middle;
+extern crate rustc_mir_dataflow;
 extern crate rustc_parse;
 extern crate rustc_session;
 extern crate rustc_span;