Added script for relation allocations [skip ci]

Author: ankane

benchmark/relation.rb

@@ -0,0 +1,14 @@
+require "bundler/setup"
+Bundler.require(:default)
+require "active_record"
+
+class Product < ActiveRecord::Base
+  searchkick
+end
+
+relation = Product.search("apples")
+
+stats = AllocationStats.trace do
+  relation.where(store_id: 1).where(in_stock: true).order(:name).limit(10).offset(50)
+end
+puts stats.allocations(alias_paths: true).to_text