Enable load() statement in the WORKSPACE file.

RELNOTES[NEW]: Skylark macros are now enabled in WORKSPACE file.

Design document at https://docs.google.com/document/d/1jKbNXOVp2T1zJD_iRnVr8k5D0xZKgO8blMVDlXOksJg/preview

Fixes #337

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MOS_MIGRATED_REVID=108860301
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
index d365738..97f6fdd 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
@@ -73,7 +73,7 @@
       Environment env, Label extensionLabel, String skylarkValueName)
       throws ConversionException {
     
-    SkyKey importFileKey = SkylarkImportLookupValue.key(extensionLabel);
+    SkyKey importFileKey = SkylarkImportLookupValue.key(extensionLabel, false);
     SkylarkImportLookupValue skylarkImportLookupValue =
         (SkylarkImportLookupValue) env.getValue(importFileKey);
     if (skylarkImportLookupValue == null) {