Introduce the transitions() function and "transition" type in Starlark.

This is under development and experimental, and is thus attached to the new flag --experimental_starlark_config_transitions. This new API is subject to change at any time until it is promoted out of "experimental".

RELNOTES: None.
PiperOrigin-RevId: 217533910
diff --git a/src/main/java/com/google/devtools/build/skydoc/SkydocMain.java b/src/main/java/com/google/devtools/build/skydoc/SkydocMain.java
index db2ec31..1ef470f 100644
--- a/src/main/java/com/google/devtools/build/skydoc/SkydocMain.java
+++ b/src/main/java/com/google/devtools/build/skydoc/SkydocMain.java
@@ -57,6 +57,7 @@
 import com.google.devtools.build.skydoc.fakebuildapi.android.FakeAndroidSkylarkCommon;
 import com.google.devtools.build.skydoc.fakebuildapi.android.FakeApkInfo.FakeApkInfoProvider;
 import com.google.devtools.build.skydoc.fakebuildapi.apple.FakeAppleCommon;
+import com.google.devtools.build.skydoc.fakebuildapi.config.FakeConfigGlobalLibrary;
 import com.google.devtools.build.skydoc.fakebuildapi.config.FakeConfigSkylarkCommon;
 import com.google.devtools.build.skydoc.fakebuildapi.cpp.FakeCcModule;
 import com.google.devtools.build.skydoc.fakebuildapi.java.FakeJavaCommon;
@@ -322,7 +323,8 @@
         new FakeAndroidNativeLibsInfoProvider());
     AppleBootstrap appleBootstrap = new AppleBootstrap(new FakeAppleCommon());
     ConfigBootstrap configBootstrap =
-        new ConfigBootstrap(new FakeConfigSkylarkCommon(), new FakeConfigApi());
+        new ConfigBootstrap(new FakeConfigSkylarkCommon(), new FakeConfigApi(),
+            new FakeConfigGlobalLibrary());
     CcBootstrap ccBootstrap = new CcBootstrap(new FakeCcModule());
     JavaBootstrap javaBootstrap = new JavaBootstrap(new FakeJavaCommon(),
         new FakeJavaInfoProvider(),