Add new skyframe function to lookup the repository given a path, and use that
to report invalid package references. Fixes #1592.

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MOS_MIGRATED_REVID=137164164
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
index 09dc01b..3e138ad 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
@@ -104,6 +104,8 @@
   public static final SkyFunctionName EXTERNAL_PACKAGE = SkyFunctionName.create("EXTERNAL_PACKAGE");
   public static final SkyFunctionName ACTION_TEMPLATE_EXPANSION =
       SkyFunctionName.create("ACTION_TEMPLATE_EXPANSION");
+  public static final SkyFunctionName LOCAL_REPOSITORY_LOOKUP =
+      SkyFunctionName.create("LOCAL_REPOSITORY_LOOKUP");
 
   public static Predicate<SkyKey> isSkyFunction(final SkyFunctionName functionName) {
     return new Predicate<SkyKey>() {