Clone AST nodes of default formal parameters prior to constant evaluation.

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 13921b7f44803e5a8da3f92ea8fd5f1d60d15f33..7e3842643a6c2b010b15db96b6227b5ba91ba4f9 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -1162,7 +1162,8 @@ class ConstantVerifier extends RecursiveAstVisitor<Object> {
           identical(dataErrorCode, CompileTimeErrorCode.CONST_EVAL_TYPE_BOOL) ||
           identical(dataErrorCode, CompileTimeErrorCode.CONST_EVAL_TYPE_INT) ||
           identical(dataErrorCode, CompileTimeErrorCode.CONST_EVAL_TYPE_NUM) ||
-          identical(dataErrorCode, CompileTimeErrorCode.RECURSIVE_COMPILE_TIME_CONSTANT) ||
+          identical(dataErrorCode,
+              CompileTimeErrorCode.RECURSIVE_COMPILE_TIME_CONSTANT) ||
           identical(dataErrorCode,
               CheckedModeCompileTimeErrorCode.CONST_CONSTRUCTOR_FIELD_TYPE_MISMATCH) ||
           identical(dataErrorCode,
@@ -10916,6 +10917,22 @@ class ResolverVisitor extends ScopedVisitor {
   }
 
   @override
+  Object visitDefaultFormalParameter(DefaultFormalParameter node) {
+    super.visitDefaultFormalParameter(node);
+    FormalParameterList parent = node.parent;
+    AstNode grandparent = parent.parent;
+    if (grandparent is ConstructorDeclaration &&
+        grandparent.constKeyword != null) {
+      // For const constructors, we need to clone the ASTs for default formal
+      // parameters, so that we can use them during constant evaluation.
+      ParameterElement element = node.element;
+      (element as ConstVariableElement).constantInitializer =
+          new ConstantAstCloner().cloneNode(node.defaultValue);
+    }
+    return null;
+  }
+
+  @override
   Object visitDoStatement(DoStatement node) {
     _overrideManager.enterScope();
     try {