Update lib/mix/lib/mix/task.compiler.ex

Author: josevalim

lib/mix/lib/mix/task.compiler.ex

@@ -323,6 +323,7 @@ defmodule Mix.Task.Compiler do
   `Mix.Task.Compiler.compilers()` are to be reenabled. This task always
   re-enables `"compile"` and `"compile.all"`.
   """
+  @doc since: "1.19.0"
   @spec reenable(compilers: compilers) :: :ok when compilers: :all | [atom()]
   def reenable(opts \\ []) do
     compilers =