Expose late-bound-attributes to Skylark.

RELNOTES: Late-bound attributes are exposed to skylark. This is a new API (`configuration_field()`) to depend on certain configuration-defined targets from skylark rules.
PiperOrigin-RevId: 174534104
diff --git a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
index 7dd8acb..bf99b43 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
@@ -1601,6 +1601,8 @@
         // that depends on non-computed default attribute values, and that condition predicate is
         // evaluated by the call to Attribute#getDefaultValue.
         attrsWithComputedDefaults.add(attr);
+      } else if (attr.isLateBound()) {
+        rule.setAttributeValue(attr, attr.getLateBoundDefault(), /*explicit=*/ false);
       } else {
         Object defaultValue = getAttributeNoncomputedDefaultValue(attr, pkgBuilder);
         rule.setAttributeValue(attr, defaultValue, /*explicit=*/ false);