Add benchmark for hash small literals

Co-Authored-By: Krzysztof Rybka <krzysztof.rybka@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66256 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

benchmark/hash_literal_small2.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+1_000_000.times.map { { "foo" => "bar", "bar" => "baz" }  }

benchmark/hash_literal_small4.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+1_000_000.times.map { { "foo" => "bar", "bar" => "baz", "baz" => "lol", "lol" => "lgtm" } }

benchmark/hash_literal_small8.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+1_000_000.times.map { { "foo" => "bar", "bar" => "baz", "baz" => "lol", "lol" => "lgtm", "lgtm" => "nope", "nope" => "ok", "ok" => "again", "again" => "wait" } }