fix issue 18631 - Allow choice to work with const arrays

std/random.d

@@ -2017,7 +2017,7 @@ Returns:
     return a `ref` to the $(D range element), otherwise it will return
     a copy.
  */
-auto ref choice(Range, RandomGen = Random)(auto ref Range range,
+auto ref choice(Range, RandomGen = Random)(inout auto ref Range range,
                                            ref RandomGen urng)
 if (isRandomAccessRange!Range && hasLength!Range && isUniformRNG!RandomGen)
 {
@@ -2055,6 +2055,13 @@ auto ref choice(Range)(auto ref Range range)
            "Choice did not return a valid element from the given Range");
 }
 
+@safe unittest // issue 18631
+{
+    const a = [0,1,2];
+    auto r = choice(a);
+    auto s = choice(cast(const)[0,1,2]);
+}
+
 @safe unittest
 {
     import std.algorithm.searching : canFind;