RELNOTES: Expose getWorkspaceName as ctx.workspace_name in Skylark.

--
MOS_MIGRATED_REVID=88137421
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java
index c2034ab..2d5bc07 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleContext.java
@@ -336,6 +336,12 @@
   public SkylarkClassObject getTargets() {
     return targetsObject;
   }
+  
+  @SkylarkCallable(name = "workspace_name", structField = true,
+      doc = "Returns the workspace name as defined in the WORKSPACE file.")
+  public String getWorkspaceName() {
+    return ruleContext.getWorkspaceName();
+  }
 
   @SkylarkCallable(name = "label", structField = true, doc = "The label of this rule.")
   public Label getLabel() {