Add test of range-based seeding of Mt19937 random generator

This is added purely in order to verify that generator behaviour will
not change with upcoming code changes.  It does not appear to match the
behaviour of the superficially similar sequence-based seeding available
for the C++11 <random> implementation of the Mersenne Twister.

Author: WebDrake

std/random.d

@@ -756,6 +756,10 @@ alias Mt19937 = MersenneTwisterEngine!(uint, 32, 624, 397, 31,
     assert(gen.front == 3499211612);
     popFrontN(gen, 9999);
     assert(gen.front == 4123659995);
+    try { gen.seed(iota(624u)); } catch (Exception) { assert(false); }
+    assert(gen.front == 3708921088u);
+    popFrontN(gen, 9999);
+    assert(gen.front == 165737292u);
 }
 
 @safe unittest