Add ConstructorBodyEntity

pkg/compiler/lib/src/kernel/kernel_backend_strategy.dart

Index: pkg/compiler/lib/src/kernel/kernel_backend_strategy.dart
diff --git a/pkg/compiler/lib/src/kernel/kernel_backend_strategy.dart b/pkg/compiler/lib/src/kernel/kernel_backend_strategy.dart
index 139cbd16f3c30b3981da47e66d2338141b5c6832..2b6c380ff945f161f0bc6cba2ab4756f522bd458 100644
--- a/pkg/compiler/lib/src/kernel/kernel_backend_strategy.dart
+++ b/pkg/compiler/lib/src/kernel/kernel_backend_strategy.dart
@@ -105,8 +105,7 @@ class KernelSsaBuilder implements SsaBuilder {
         _compiler.backendStrategy.closureDataLookup,
         // TODO(redemption): Support these:
         const SourceInformationBuilder(),
-        null, // Function node used as capture scope id.
-        targetIsConstructorBody: false);
+        null); // Function node used as capture scope id.
     return builder.build();
   }
 }