System.Random is way too lazy

randomRs is too lazy, generates lists of large lazy-state thunks, rather than lists of strict values.

Test program is attached.

Also, randomIO is too lazy, and builds up huge thunks. Using (randomIO >>= evaluate) is fine, however.

Fails with stack overflow:

  rs <- replicateM 1000000 evaluate :: IO [Int]
  print $ last rs

Works:

  rs <- replicateM 1000000 (evaluate =<< randomIO) :: IO [Int]
  print $ last rs