Remove peeking from parseTypedef and parseClassOrNamedMixinApplication.

pkg/analyzer/lib/src/fasta/ast_builder.dart

Index: pkg/analyzer/lib/src/fasta/ast_builder.dart
diff --git a/pkg/analyzer/lib/src/fasta/ast_builder.dart b/pkg/analyzer/lib/src/fasta/ast_builder.dart
index b3896c96a8727f1d38e1b56e7093a83ddf815c77..67f6f912af0e339720e44d3ba504f0c6f28e02e4 100644
--- a/pkg/analyzer/lib/src/fasta/ast_builder.dart
+++ b/pkg/analyzer/lib/src/fasta/ast_builder.dart
@@ -227,8 +227,6 @@ class AstBuilder extends ScopeListener {
           assert(element != null);
           identifier.staticElement = element;
         }
-      } else if (context == IdentifierContext.classDeclaration) {
-        className = identifier.name;
       }
       push(identifier);
     }
@@ -1337,6 +1335,12 @@ class AstBuilder extends ScopeListener {
         beginToken, popList(memberCount) ?? <ClassMember>[], endToken));
   }
 
+  @override
+  void beginClassDeclaration(Token beginToken, Token name) {
+    assert(className == null);
+    className = name.lexeme;
+  }
+
   @override
   void endClassDeclaration(
       int interfacesCount,