Import CSV 3.0.2

This includes performance improvement especially writing. Writing is
about 2 times faster.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66507 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/csv/match_p.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+# This provides String#match? and Regexp#match? for Ruby 2.3.
+unless String.method_defined?(:match?)
+  class CSV
+    module MatchP
+      refine String do
+        def match?(pattern)
+          self =~ pattern
+        end
+      end
+
+      refine Regexp do
+        def match?(string)
+          self =~ string
+        end
+      end
+    end
+  end
+end