base: Make the random number generator public

There are cases where we need a random number generator engine. The
Random class has such an engine but its interface currently only
allows for generating random numbers. To make sure we can reuse the
same random number generator in as many places as possible this patch
makes the engine in the Random class public.

Change-Id: I80153dd39f5b0d12537e4c0cf54773e7725b2a94
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47859
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/base/random.hh

@@ -61,12 +61,13 @@ class Checkpoint;
 class Random : public Serializable
 {
 
-  private:
-
-    std::mt19937_64 gen;
-
   public:
 
+    /**
+     * @ingroup api_base_utils
+     */
+    std::mt19937_64 gen;
+
     /**
      * @ingroup api_base_utils
      * @{