Thread.exclusive: delete

Has been deprecated since 2069c9e031.

[Feature #17125][ruby-core:99636]

prelude.rb

@@ -1,18 +1,3 @@
-class << Thread
-  # call-seq:
-  #    Thread.exclusive { block }   -> obj
-  #
-  # Wraps the block in a single, VM-global Mutex.synchronize, returning the
-  # value of the block. A thread executing inside the exclusive section will
-  # only block other threads which also use the Thread.exclusive mechanism.
-  def exclusive(&block) end if false
-  mutex = Mutex.new # :nodoc:
-  define_method(:exclusive) do |&block|
-    warn "Thread.exclusive is deprecated, use Thread::Mutex", uplevel: 1
-    mutex.synchronize(&block)
-  end
-end
-
 class Binding
   # :nodoc:
   def irb

spec/ruby/core/thread/exclusive_spec.rb

@@ -1,5 +1,6 @@
 require_relative '../../spec_helper'
 
+ruby_version_is ''...'2.8' do
   describe "Thread.exclusive" do
     before :each do
       ScratchPad.clear
@@ -45,3 +46,4 @@ describe "Thread.exclusive" do
       end
     end
   end
+end