Fix clang template weirdness.

src/hashmap.h

Index: src/hashmap.h
diff --git a/src/hashmap.h b/src/hashmap.h
index 0d51db2dde860ca5f265800381f2b49237114d8c..5aeb8951ed38f0237df5b7d3d75621667514007d 100644
--- a/src/hashmap.h
+++ b/src/hashmap.h
@@ -331,7 +331,7 @@ class TemplateHashMap: private TemplateHashMapImpl<AllocationPolicy> {
   Iterator begin() const { return Iterator(this, this->Start()); }
   Iterator end() const { return Iterator(this, NULL); }
   Iterator find(Key* key, bool insert = false) {
-    return Iterator(this, Lookup(key, key->Hash(), insert));
+    return Iterator(this, this->Lookup(key, key->Hash(), insert));
   }
 };