Handle const Symbol(...) in kernel_impact

pkg/compiler/lib/src/ssa/kernel_impact.dart

Index: pkg/compiler/lib/src/ssa/kernel_impact.dart
diff --git a/pkg/compiler/lib/src/ssa/kernel_impact.dart b/pkg/compiler/lib/src/ssa/kernel_impact.dart
index 8f4d619dd7317b7cbe70f622283d8ee9efdc8f86..a564ca5e7df1974f4b12bc61997baefc6cea766c 100644
--- a/pkg/compiler/lib/src/ssa/kernel_impact.dart
+++ b/pkg/compiler/lib/src/ssa/kernel_impact.dart
@@ -8,6 +8,7 @@ import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
 import '../constants/expressions.dart';
+import '../constants/values.dart';
 import '../common_elements.dart';
 import '../elements/types.dart';
 import '../elements/elements.dart' show AstElement, ResolvedAst;
@@ -280,6 +281,19 @@ class KernelImpactBuilder extends ir.Visitor {
     if (type.typeArguments.any((DartType type) => !type.isDynamic)) {
       impactBuilder.registerFeature(Feature.TYPE_VARIABLE_BOUNDS_CHECK);
     }
+    if (isConst && commonElements.isSymbolConstructor(constructor)) {
+      ConstantValue value =
+          elementAdapter.getConstantValue(node.arguments.positional.first);
+      if (!value.isString) {
+        throw new SpannableAssertionFailure(
+            CURRENT_ELEMENT_SPANNABLE,
+            "Unexpected constant value in const Symbol(...) call: "
+            "${value.toStructuredText()}");
+      }
+      StringConstantValue stringValue = value;
+      impactBuilder
+          .registerConstSymbolName(stringValue.primitiveValue.slowToString());
+    }
   }
 
   @override