Introduce improvements in deduplicating crates

fixes rust-lang#15656 . With this commit we have a more relaxed way
of comparing to crates for equality. If two crates are `almost_equal`
then deduplication takes place.

crates/base-db/src/input.rs

@@ -649,12 +649,6 @@ impl CrateGraph {
             });
             crate_data.dependencies.sort_by_key(|dep| dep.crate_id);
             let res = self.arena.iter().find_map(|(id, data)| {
-                let name = data.display_name.as_ref().unwrap().crate_name.clone();
-                let name2 = crate_data.display_name.as_ref().unwrap().crate_name.clone();
-                if name.to_string() == "std" && name2.to_string() == "std" {
-                    dbg!(data.almost_eq(crate_data), &data, &crate_data);
-                }
-
                 if data.almost_eq(crate_data) {
                     // If this ever fails then all we need to do is to replace crate_data with data.
                     assert!(data.origin <= crate_data.origin);