Remove misleading docs.

They claim you can't use `match` matcher within` match` block,
but this now works.

features/custom_matchers/define_matcher.feature

@@ -338,31 +338,3 @@ Feature: define matcher
       | 4 examples, 2 failures               |
       | expected 9 to be a multiple of 2     |
       | expected 9 not to be a multiple of 3 |
-
-  Scenario: matching against a regular expression
-    Given a file named "regular_expression_matcher_spec.rb" with:
-      """ruby
-      # Due to Ruby's method dispatch mechanism, use the `#match_regex` alias
-      # rather than the `#match` matcher when defining custom matchers via the
-      # DSL.
-
-      RSpec::Matchers.define :be_valid_us_zipcode do
-        match do |actual|
-          expect(actual).to match_regex(/\A\d{5}(-\d{4})?\z/)
-        end
-      end
-
-      describe "30316" do
-        it { should be_valid_us_zipcode }
-      end
-
-      describe "30316-0001" do
-        it { should be_valid_us_zipcode }
-      end
-
-      describe "1000-61303" do
-        it { should_not be_valid_us_zipcode }
-      end
-      """
-    When I run `rspec regular_expression_matcher_spec.rb`
-    Then the stdout should contain "3 examples, 0 failures"

lib/rspec/matchers.rb

@@ -435,18 +435,9 @@ def include(*expected)
     #
     #   expect(email).to   match(/^([^\s]+)((?:[-a-z0-9]+\.)+[a-z]{2,})$/i)
     #   expect(email).to   match("@example.com")
-    #   expect(zipcode).to match_regex(/\A\d{5}(-\d{4})?\z/)
-    #   expect(zipcode).to match_regex("90210")
-    #
-    # @note Due to Ruby's method dispatch mechanism, using the `#match` matcher
-    # within a custom matcher defined via the matcher DSL
-    # (`RSpec::Matcher.define`) will result Ruby calling the wrong `#match`
-    # method and raising an `ArgumentError`. Instead, use the aliased
-    # `#match_regex` method.
     def match(expected)
       BuiltIn::Match.new(expected)
     end
-
     alias_method :match_regex, :match
 
     # With no args, matches if any error is raised.