Auto merge of #5937 - montrivo:option_if_let_else, r=flip1995

option_if_let_else - distinguish pure from impure else expressions

Addresses partially #5821.

changelog: improve the lint `option_if_let_else`. Suggest `map_or` or `map_or_else` based on the else expression purity.

diff --cc clippy_lints/src/methods/mod.rs
Simple merge

diff --cc clippy_lints/src/option_if_let_else.rs
index 60e5e7bfed398e03ccd9226b3ce47d30b0edae41,5e2652b48cb2aeaf6d876bd36852e625b17ac1ba..4a3eb9c983a11617114d4231a2b58e74133b1279
--- 1/clippy_lints/src/option_if_let_else.rs
--- 2/clippy_lints/src/option_if_let_else.rs
+++ b/clippy_lints/src/option_if_let_else.rs
@@@ -1,6 -1,7 +1,7 @@@
  use crate::utils;
+ use crate::utils::eager_or_lazy;
  use crate::utils::sugg::Sugg;
 -use crate::utils::{match_type, paths, span_lint_and_sugg};
 +use crate::utils::{is_type_diagnostic_item, paths, span_lint_and_sugg};
  use if_chain::if_chain;
  
  use rustc_errors::Applicability;

diff --cc clippy_lints/src/utils/mod.rs
Simple merge