A minor refactoring in FileConfiguredTarget.

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MOS_MIGRATED_REVID=91875924
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
index 0e024b1..c915cae 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
@@ -41,6 +41,13 @@
   }
 
   /**
+   * Creates an instance that contains one single executable and no other files.
+   */
+  public static FilesToRunProvider fromSingleArtifact(Label label, Artifact artifact) {
+    return new FilesToRunProvider(label, ImmutableList.of(artifact), null, artifact);
+  }
+
+  /**
    * Returns the label that is associated with this piece of information.
    *
    * <p>This is usually the label of the target that provides the information.