move clone model to Extend.qll

Author: erik-krogh

javascript/ql/src/javascript.qll

@@ -78,7 +78,6 @@ import semmle.javascript.frameworks.ComposedFunctions
 import semmle.javascript.frameworks.Classnames
 import semmle.javascript.frameworks.ClassValidator
 import semmle.javascript.frameworks.ClientRequests
-import semmle.javascript.frameworks.Clone
 import semmle.javascript.frameworks.ClosureLibrary
 import semmle.javascript.frameworks.CookieLibraries
 import semmle.javascript.frameworks.Credentials

javascript/ql/src/semmle/javascript/Extend.qll

@@ -174,3 +174,17 @@ private class ExtendCallTaintStep extends TaintTracking::SharedTaintStep {
     )
   }
 }
+
+private import semmle.javascript.dataflow.internal.PreCallGraphStep
+
+/**
+ * A step for the `clone` package.
+ */
+private class CloneStep extends PreCallGraphStep {
+  override predicate step(DataFlow::Node pred, DataFlow::Node succ) {
+    exists(DataFlow::CallNode call | call = DataFlow::moduleImport("clone").getACall() |
+      pred = call.getArgument(0) and
+      succ = call
+    )
+  }
+}