Ensure that all aspects which (even very indirectly) call
CppHelper.getToolchainFromPlatformConstraints  declare that they require a cc
toolchain.

PiperOrigin-RevId: 194580065
diff --git a/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java b/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java
index 1b537e4..c299e64 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java
@@ -19,7 +19,9 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableMultimap;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterables;
 import com.google.common.collect.LinkedHashMultimap;
+import com.google.common.collect.Lists;
 import com.google.common.collect.Multimap;
 import com.google.common.collect.SetMultimap;
 import com.google.devtools.build.lib.analysis.config.transitions.ConfigurationTransition;
@@ -494,6 +496,12 @@
     }
 
     /** Adds the given toolchains as requirements for this aspect. */
+    public Builder addRequiredToolchains(Label... toolchainLabels) {
+      Iterables.addAll(this.requiredToolchains, Lists.newArrayList(toolchainLabels));
+      return this;
+    }
+
+    /** Adds the given toolchains as requirements for this aspect. */
     public Builder addRequiredToolchains(List<Label> requiredToolchains) {
       this.requiredToolchains.addAll(requiredToolchains);
       return this;