move tests to testament (#16101)

* move tests to testament

* minor

* fix random

* disable test random

tests/stdlib/trandom.nim

@@ -0,0 +1,59 @@
+discard """
+  action: compile
+"""
+
+import random
+
+proc main =
+  var occur: array[1000, int]
+
+  var x = 8234
+  for i in 0..100_000:
+    x = rand(high(occur))
+    inc occur[x]
+  for i, oc in occur:
+    if oc < 69:
+      doAssert false, "too few occurrences of " & $i
+    elif oc > 150:
+      doAssert false, "too many occurrences of " & $i
+
+  when false:
+    var rs: RunningStat
+    for j in 1..5:
+      for i in 1 .. 1_000:
+        rs.push(gauss())
+      echo("mean: ", rs.mean,
+        " stdDev: ", rs.standardDeviation(),
+        " min: ", rs.min,
+        " max: ", rs.max)
+      rs.clear()
+
+  var a = [0, 1]
+  shuffle(a)
+  doAssert a[0] == 1
+  doAssert a[1] == 0
+
+  doAssert rand(0) == 0
+  doAssert sample("a") == 'a'
+
+  when compileOption("rangeChecks"):
+    try:
+      discard rand(-1)
+      doAssert false
+    except RangeDefect:
+      discard
+
+    try:
+      discard rand(-1.0)
+      doAssert false
+    except RangeDefect:
+      discard
+
+
+  # don't use causes integer overflow
+  doAssert compiles(rand[int](low(int) .. high(int)))
+
+randomize(223)
+
+for i in 0 .. 10:
+  main()