Filter middleman artifacts from NamedArtifactGroup

PiperOrigin-RevId: 199786555
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/NamedArtifactGroup.java b/src/main/java/com/google/devtools/build/lib/runtime/NamedArtifactGroup.java
index 700ab65..b990c15 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/NamedArtifactGroup.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/NamedArtifactGroup.java
@@ -59,6 +59,9 @@
     BuildEventStreamProtos.NamedSetOfFiles.Builder builder =
         BuildEventStreamProtos.NamedSetOfFiles.newBuilder();
     for (Artifact artifact : view.directs()) {
+      if (artifact.isMiddlemanArtifact()) {
+        continue;
+      }
       String name = artifact.getRootRelativePathString();
       String uri = pathConverter.apply(artifact.getPath());
       builder.addFiles(BuildEventStreamProtos.File.newBuilder().setName(name).setUri(uri));