Give a deprecation warning

Author: vchuravy

base/Base.jl

@@ -377,10 +377,6 @@ using .CoreLogging
 
 include("env.jl")
 
-# functions defined in Random
-function rand end
-function randn end
-
 # I/O
 include("libuv.jl")
 include("asyncevent.jl")

base/deprecated.jl

@@ -392,4 +392,9 @@ end
 @deprecate permute!!(a, p::AbstractVector{<:Integer}) permute!(a, p) false
 @deprecate invpermute!!(a, p::AbstractVector{<:Integer}) invpermute!(a, p) false
 
+# functions defined in Random
+function rand end
+function randn end
+export rand, randn
+
 # END 1.11 deprecations

base/exports.jl

@@ -994,10 +994,6 @@ export
     unsafe_store!,
     unsafe_swap!,
 
-# implemented in Random module
-    rand,
-    randn,
-
 # Macros
     # parser internal
     @__FILE__,

base/stubs.jl

@@ -1,6 +1,21 @@
 module Stubs
 
+macro stub(old, mod)
+    dep_message = """: `$old` has been moved to the standard library package `$mod`.
+                        Add `using $mod` to your imports."""
+    return Expr(:toplevel,
+        quote
+            import Base: $old
+            function $(esc(old))(args...)
+                Base.depwarn($dep_message, $(QuoteNode(old)))
+                Base.invoke_in_world($(esc(:delay_initialize))(), $(esc(old)), args...)
+            end
+            Base.Docs.getdoc(::typeof($(esc(old)))) = ($(esc(:delay_initialize))(); nothing)
+        end)
+end
+
 module Random
+    import ..Stubs: @stub
     let Random_PkgID = Base.PkgId(Base.UUID(0x9a3f8284_a2c9_5f02_9a11_845980a1fd5c), "Random")
         RANDOM_MODULE_REF = Ref{Module}()
 
@@ -12,20 +27,10 @@ module Random
             return ccall(:jl_module_world, Csize_t, (Any,), RANDOM_MODULE_REF[])
         end
     end
-
-    import Base: rand, randn
-    function rand(args...)
-        Base.invoke_in_world(delay_initialize(), rand, args...)
-    end
-
-    function randn(args...)
-        Base.invoke_in_world(delay_initialize(), randn, args...)
-    end
+    @stub rand Random
+    @stub randn Random
 end
 
-Base.Docs.getdoc(::typeof(Base.rand)) = (Random.delay_initialize(); nothing)
-Base.Docs.getdoc(::typeof(Base.randn)) = (Random.delay_initialize(); nothing)
-
 function delete_stubs(mod)
     for name in names(mod, imported=true)
         if name == :delay_initialize