Revert "Only call MirrorsData.retainMetadata* from codegen"

pkg/compiler/lib/src/js_backend/mirrors_data.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import '../closure.dart';
 import '../common.dart';
 import '../common_elements.dart';
 import '../compiler.dart';
 import '../constants/values.dart';
 import '../elements/elements.dart';
@@ skipping 106 matching lines @@
   /// This property is used to tag emitted elements with a marker which is
   /// checked by the runtime system to throw an exception if an element is
   /// accessed (invoked, get, set) that is not accessible for the reflective
   /// system.
   bool isMemberAccessibleByReflection(MemberEntity element);
 
   // TODO(johnniwinther): Remove this.
   @deprecated
   bool isAccessibleByReflection(Element element);
 
-  bool retainMetadataOfLibrary(LibraryEntity element);
+  bool retainMetadataOfLibrary(LibraryEntity element,
+      {bool addForEmission: true});
   bool retainMetadataOfTypedef(TypedefElement element);
   bool retainMetadataOfClass(ClassEntity element);
   bool retainMetadataOfMember(MemberEntity element);
   bool retainMetadataOfParameter(ParameterElement element);
 
   bool invokedReflectively(Element element);
 
   /// Returns true if this element has to be enqueued due to
   /// mirror usage. Might be a subset of [referencedFromMirrorSystem] if
   /// normal tree shaking is still active ([isTreeShakingDisabled] is false).
@@ skipping 145 matching lines @@
       hasRetainedMetadata = true;
       if (isTypedefReferencedFromMirrorSystem(element)) {
         _retainMetadataOf(element);
         return true;
       }
     }
     return false;
   }
 
   @override
-  bool retainMetadataOfLibrary(LibraryElement element) {
+  bool retainMetadataOfLibrary(LibraryElement element,
+      {bool addForEmission: true}) {
     if (mustRetainMetadata) {
       hasRetainedMetadata = true;
       if (isLibraryReferencedFromMirrorSystem(element)) {
-        _retainMetadataOf(element);
+        _retainMetadataOf(element, addForEmission: addForEmission);
         return true;
       }
     }
     return false;
   }
 
-  void _retainMetadataOf(Element element) {
-    assert(_compiler.phase == Compiler.PHASE_COMPILING);
+  void _retainMetadataOf(Element element, {bool addForEmission: true}) {
     for (MetadataAnnotation metadata in element.metadata) {
+      metadata.ensureResolved(_compiler.resolution);
       ConstantValue constant = _constants.getConstantValueForMetadata(metadata);
-      CodegenWorldBuilder worldBuilder = _compiler.codegenWorldBuilder;
-      worldBuilder.addCompileTimeConstantForEmission(constant);
+      if (addForEmission) {
+        CodegenWorldBuilder worldBuilder = _compiler.codegenWorldBuilder;
+        worldBuilder.addCompileTimeConstantForEmission(constant);
+      }
     }
   }
 
   bool invokedReflectively(Element element) {
     if (element.isParameter) {
       ParameterElement parameter = element;
       if (invokedReflectively(parameter.functionDeclaration)) return true;
     }
 
     if (element.isField) {
@@ skipping 377 matching lines @@
   }
 
   /// Called when `const Symbol(name)` is seen.
   void registerConstSymbol(String name) {
     symbolsUsed.add(name);
     if (name.endsWith('=')) {
       symbolsUsed.add(name.substring(0, name.length - 1));
     }
   }
 }