Clone IVariables in IVariableList clone

Allows for not recreating a new `IVariable` for every assign operation.

Author: Pieter12345

src/main/java/com/laytonsmith/core/constructs/IVariable.java

@@ -96,6 +96,14 @@ public IVariable clone() throws CloneNotSupportedException {
 		return clone;
 	}
 
+	/**
+	 * Create a clone of this {@link IVariable} using the same variable value reference.
+	 * @return The clone.
+	 */
+	public IVariable shallowClone() {
+		return new IVariable(type, name, varValue, definedTarget);
+	}
+
 	@Override
 	public boolean isDynamic() {
 		return true;

src/main/java/com/laytonsmith/core/constructs/IVariableList.java

@@ -133,7 +133,9 @@ public String toString() {
 	@Override
 	public IVariableList clone() {
 		IVariableList clone = new IVariableList(this);
-		clone.varList = new HashMap<>(varList);
+		for(IVariable var : varList.values()) {
+			clone.set(var.shallowClone());
+		}
 		return clone;
 	}