Add ConstantUse to WorldImpact

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

Index: pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
diff --git a/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart b/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
index b48228ab13088f41a7efdef25d317156c0cde1a4..68e852c63badbb39cb04cb8082e48b9cb9dd5797 100644
--- a/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
+++ b/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
@@ -152,9 +152,7 @@ class MirrorsAnalysis {
           Dependency dependency =
               new Dependency(constant, metadata.annotatedElement);
           metadataConstants.add(dependency);
-          backend.computeImpactForCompileTimeConstant(
-              dependency.constant, impactBuilder,
-              forResolution: enqueuer.isResolutionQueue);
+          impactBuilder.registerConstantUse(new ConstantUse.mirrors(constant));
         }
 
         // TODO(johnniwinther): We should have access to all recently processed
@@ -162,9 +160,8 @@ class MirrorsAnalysis {
         processMetadata(enqueuer.processedEntities, registerMetadataConstant);
       } else {
         for (Dependency dependency in metadataConstants) {
-          backend.computeImpactForCompileTimeConstant(
-              dependency.constant, impactBuilder,
-              forResolution: enqueuer.isResolutionQueue);
+          impactBuilder.registerConstantUse(
+              new ConstantUse.mirrors(dependency.constant));
         }
         metadataConstants.clear();
       }