Stop concatenating prefixes and identifiers when performing lookup (issue 26069)

pkg/analyzer/lib/src/dart/ast/ast.dart

Index: pkg/analyzer/lib/src/dart/ast/ast.dart
diff --git a/pkg/analyzer/lib/src/dart/ast/ast.dart b/pkg/analyzer/lib/src/dart/ast/ast.dart
index 78daa6fce39a0137748d6c0ec8c46bcd8b6093cd..2825ef56b73733f1ccd3369cfdee168878951e51 100644
--- a/pkg/analyzer/lib/src/dart/ast/ast.dart
+++ b/pkg/analyzer/lib/src/dart/ast/ast.dart
@@ -8204,6 +8204,13 @@ class PrefixedIdentifierImpl extends IdentifierImpl
     _identifier = _becomeParentOf(identifier);
   }
 
+  /**
+   * Initialize a newly created prefixed identifier that does not take ownership
+   * of the components. The resulting node is only for temporary use, such as by
+   * resolution.
+   */
+  PrefixedIdentifierImpl.temp(this._prefix, this._identifier) : period = null;
+
   @override
   Token get beginToken => _prefix.beginToken;