Fix even more clippy warnings

compiler/rustc_errors/src/json.rs

@@ -136,10 +136,7 @@ impl Emitter for JsonEmitter {
     }
 
     fn should_show_explain(&self) -> bool {
-        match self.json_rendered {
-            HumanReadableErrorType::Short(_) => false,
-            _ => true,
-        }
+        !matches!(self.json_rendered, HumanReadableErrorType::Short(_))
     }
 }
 

compiler/rustc_errors/src/lib.rs

@@ -91,10 +91,7 @@ pub enum SuggestionStyle {
 
 impl SuggestionStyle {
     fn hide_inline(&self) -> bool {
-        match *self {
-            SuggestionStyle::ShowCode => false,
-            _ => true,
-        }
+        !matches!(*self, SuggestionStyle::ShowCode)
     }
 }
 
@@ -1038,10 +1035,7 @@ impl Level {
     }
 
     pub fn is_failure_note(&self) -> bool {
-        match *self {
-            FailureNote => true,
-            _ => false,
-        }
+        matches!(*self, FailureNote)
     }
 }
 

compiler/rustc_errors/src/snippet.rs

@@ -158,10 +158,7 @@ impl Annotation {
 
     pub fn takes_space(&self) -> bool {
         // Multiline annotations always have to keep vertical space.
-        match self.annotation_type {
-            AnnotationType::MultilineStart(_) | AnnotationType::MultilineEnd(_) => true,
-            _ => false,
-        }
+        matches!(self.annotation_type, AnnotationType::MultilineStart(_) | AnnotationType::MultilineEnd(_))
     }
 }