rename Parallel to Distributed (#20486)

Author: amitmurthy

base/parallel/Parallel.jl renamed to base/distributed/Distributed.jl

@@ -1,6 +1,6 @@
 # This file is a part of Julia. License is MIT: http://julialang.org/license
 
-module Parallel
+module Distributed
 
 # imports for extension
 import Base: getindex, wait, put!, take!, fetch, isready, push!, length,

base/parallel/cluster.jl renamed to base/distributed/cluster.jl

@@ -879,7 +879,7 @@ function disable_nagle(sock)
     @static if is_linux()
         # tcp_quickack is a linux only option
         if ccall(:jl_tcp_quickack, Cint, (Ptr{Void}, Cint), sock.handle, 1) < 0
-            warn_once("Parallel networking unoptimized ( Error enabling TCP_QUICKACK : ", Libc.strerror(Libc.errno()), " )")
+            warn_once("Networking unoptimized ( Error enabling TCP_QUICKACK : ", Libc.strerror(Libc.errno()), " )")
         end
     end
 end