Drop Concurrent::Future and top-level methods delay, future, lazy

spec/std/http/server/server_spec.cr

@@ -2,6 +2,7 @@ require "../spec_helper"
 require "http/server"
 require "http/client/response"
 require "../../../support/ssl"
+require "../../../support/channel"
 
 # TODO: replace with `HTTP::Client` once it supports connecting to Unix socket (#2735)
 private def unix_request(path)
@@ -72,7 +73,7 @@ describe HTTP::Server do
     end
     sleep 0.1
 
-    delay(1) { ch.send :timeout }
+    schedule_timeout ch
 
     TCPSocket.open(address.address, address.port) { }
 

spec/std/io/io_spec.cr

@@ -1,4 +1,6 @@
 require "../spec_helper"
+require "../../support/channel"
+
 {% unless flag?(:win32) %}
   require "big"
 {% end %}
@@ -857,7 +859,7 @@ describe IO do
           ch.send :end
         end
 
-        delay(1) { ch.send :timeout }
+        schedule_timeout ch
 
         ch.receive.should eq(:start)
         wait_until_blocked f
@@ -880,7 +882,7 @@ describe IO do
           ch.send :end
         end
 
-        delay(1) { ch.send :timeout }
+        schedule_timeout ch
 
         ch.receive.should eq(:start)
         wait_until_blocked f

spec/std/socket/unix_server_spec.cr

@@ -1,6 +1,7 @@
 require "../spec_helper"
 require "socket"
 require "../../support/fibers"
+require "../../support/channel"
 require "../../support/tempfile"
 
 describe UNIXServer do
@@ -81,7 +82,7 @@ describe UNIXServer do
         ch = Channel(Symbol).new(1)
         exception = nil
 
-        delay(1) { ch.send :timeout }
+        schedule_timeout ch
 
         f = spawn do
           begin
@@ -126,7 +127,7 @@ describe UNIXServer do
         ch = Channel(Symbol).new(1)
         ret = :initial
 
-        delay(1) { ch.send :timeout }
+        schedule_timeout ch
 
         f = spawn do
           ch.send :begin

spec/support/channel.cr

@@ -0,0 +1,6 @@
+def schedule_timeout(c : Channel(Symbol))
+  spawn do
+    sleep 1
+    c.send(:timeout)
+  end
+end

spec/win32_std_spec.cr

@@ -22,7 +22,6 @@ require "./std/class_spec.cr"
 require "./std/colorize_spec.cr"
 require "./std/comparable_spec.cr"
 require "./std/complex_spec.cr"
-require "./std/concurrent/future_spec.cr"
 # require "./std/concurrent/select_spec.cr" (failed to run)
 require "./std/concurrent_spec.cr"
 # require "./std/crc32_spec.cr" (failed linking)

src/concurrent.cr

@@ -1,7 +1,6 @@
 require "fiber"
 require "channel"
 require "crystal/scheduler"
-require "./concurrent/*"
 
 # Blocks the current fiber for the specified number of seconds.
 #