Introduce --incompatible_no_transitive_loads

With flag set, loaded symbols are not automatically re-exported.

#5636

RELNOTES: None.
PiperOrigin-RevId: 214776940
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Eval.java b/src/main/java/com/google/devtools/build/lib/syntax/Eval.java
index a91ffae..d7e30dd 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Eval.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Eval.java
@@ -121,7 +121,7 @@
       throw new EvalException(node.getLocation(), "Keyword-only argument is forbidden.");
     }
 
-    env.update(
+    env.updateAndExport(
         node.getIdentifier().getName(),
         new UserDefinedFunction(
             node.getIdentifier().getName(),