Unify manual_unwrap_or and manual_unwrap_or_default code

Both lints share a lot of characteristics but were implemented in
unrelated ways. This unifies them, saving around 100 SLOC in the
process, and making one more test trigger the lint. Also, this removes
useless blocks in suggestions.

Author: samueltardieu

clippy_lints/src/declared_lints.rs

@@ -335,7 +335,6 @@ pub static LINTS: &[&crate::LintInfo] = &[
     crate::manual_slice_size_calculation::MANUAL_SLICE_SIZE_CALCULATION_INFO,
     crate::manual_string_new::MANUAL_STRING_NEW_INFO,
     crate::manual_strip::MANUAL_STRIP_INFO,
-    crate::manual_unwrap_or_default::MANUAL_UNWRAP_OR_DEFAULT_INFO,
     crate::map_unit_fn::OPTION_MAP_UNIT_FN_INFO,
     crate::map_unit_fn::RESULT_MAP_UNIT_FN_INFO,
     crate::match_result_ok::MATCH_RESULT_OK_INFO,
@@ -345,6 +344,7 @@ pub static LINTS: &[&crate::LintInfo] = &[
     crate::matches::MANUAL_MAP_INFO,
     crate::matches::MANUAL_OK_ERR_INFO,
     crate::matches::MANUAL_UNWRAP_OR_INFO,
+    crate::matches::MANUAL_UNWRAP_OR_DEFAULT_INFO,
     crate::matches::MATCH_AS_REF_INFO,
     crate::matches::MATCH_BOOL_INFO,
     crate::matches::MATCH_LIKE_MATCHES_MACRO_INFO,

clippy_lints/src/lib.rs

@@ -226,7 +226,6 @@ mod manual_rotate;
 mod manual_slice_size_calculation;
 mod manual_string_new;
 mod manual_strip;
-mod manual_unwrap_or_default;
 mod map_unit_fn;
 mod match_result_ok;
 mod matches;
@@ -960,7 +959,6 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
     store.register_early_pass(|| Box::new(multiple_bound_locations::MultipleBoundLocations));
     store.register_late_pass(move |_| Box::new(assigning_clones::AssigningClones::new(conf)));
     store.register_late_pass(|_| Box::new(zero_repeat_side_effects::ZeroRepeatSideEffects));
-    store.register_late_pass(|_| Box::new(manual_unwrap_or_default::ManualUnwrapOrDefault));
     store.register_late_pass(|_| Box::new(integer_division_remainder_used::IntegerDivisionRemainderUsed));
     store.register_late_pass(move |_| Box::new(macro_metavars_in_unsafe::ExprMetavarsInUnsafe::new(conf)));
     store.register_late_pass(move |_| Box::new(string_patterns::StringPatterns::new(conf)));