Merge #9761

9761: feat: Show coerced types on type hover r=Veykril a=Veykril

This applies to both the ranged hover request as well as the normal hover type fallback.
![image](https://user-images.githubusercontent.com/3757771/127883884-2935b624-a3e5-4f35-861a-7d6d3266d187.png)
![image](https://user-images.githubusercontent.com/3757771/127883951-4ff96b6b-7576-4886-887b-1198c1121841.png)

We unfortunately have to leave out syntax highlighting here as otherwise the `Type` and `Coerced` words in the hover will get colored.

Note that this does not show all the coercions yet(and almost no pattern coercions) as not all coercion adjustments are implemented yet.

Closes #2677

Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

Author: bors[bot]

crates/hir/src/semantics.rs

@@ -225,7 +225,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.type_of_pat(pat)
     }
 
-    pub fn type_of_pat_with_coercion(&self, expr: &ast::Pat) -> Option<Type> {
+    pub fn type_of_pat_with_coercion(&self, expr: &ast::Pat) -> Option<(Type, bool)> {
         self.imp.type_of_pat_with_coercion(expr)
     }
 
@@ -577,7 +577,7 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(pat.syntax()).type_of_pat(self.db, pat)
     }
 
-    fn type_of_pat_with_coercion(&self, pat: &ast::Pat) -> Option<Type> {
+    fn type_of_pat_with_coercion(&self, pat: &ast::Pat) -> Option<(Type, bool)> {
         self.analyze(pat.syntax()).type_of_pat_with_coercion(self.db, pat)
     }
 

crates/hir/src/source_analyzer.rs

@@ -147,15 +147,15 @@ impl SourceAnalyzer {
         &self,
         db: &dyn HirDatabase,
         pat: &ast::Pat,
-    ) -> Option<Type> {
+    ) -> Option<(Type, bool)> {
         let pat_id = self.pat_id(pat)?;
         let infer = self.infer.as_ref()?;
-        let ty = infer
+        let (ty, coerced) = infer
             .pat_adjustments
             .get(&pat_id)
-            .and_then(|adjusts| adjusts.last().map(|adjust| &adjust.target))
-            .unwrap_or_else(|| &infer[pat_id]);
-        Type::new_with_resolver(db, &self.resolver, ty.clone())
+            .and_then(|adjusts| adjusts.last().map(|adjust| (&adjust.target, true)))
+            .unwrap_or_else(|| (&infer[pat_id], false));
+        Type::new_with_resolver(db, &self.resolver, ty.clone()).zip(Some(coerced))
     }
 
     pub(crate) fn type_of_self(