Add managed_directories attribute to workspace() function.

This is only a part of the incrementally updated user-owned directory feature; that is why the parsed value is not yet used in computations.

- Under --experimental_allow_incremental_repository_updates flag.
- Parse results are put into WorkspaceFileValue map field.

PiperOrigin-RevId: 244819268
diff --git a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
index 08eeec2..7e2df6f 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
@@ -118,6 +118,7 @@
   private static StarlarkSemanticsOptions buildRandomOptions(Random rand) throws Exception {
     return parseOptions(
         // <== Add new options here in alphabetic order ==>
+        "--experimental_allow_incremental_repository_updates=" + rand.nextBoolean(),
         "--experimental_build_setting_api=" + rand.nextBoolean(),
         "--experimental_cc_skylark_api_enabled_packages="
             + rand.nextDouble()
@@ -172,6 +173,7 @@
   private static StarlarkSemantics buildRandomSemantics(Random rand) {
     return StarlarkSemantics.builder()
         // <== Add new options here in alphabetic order ==>
+        .experimentalAllowIncrementalRepositoryUpdates(rand.nextBoolean())
         .experimentalBuildSettingApi(rand.nextBoolean())
         .experimentalCcSkylarkApiEnabledPackages(
             ImmutableList.of(String.valueOf(rand.nextDouble()), String.valueOf(rand.nextDouble())))