Reorganize tests and benchmark scripts.

Mainly to get rid of one top level directory. But this will
also be useful when there are tests of the embedding API.

test/core/range/iterate.wren

@@ -0,0 +1,35 @@
+// Inclusive.
+var range = 1..3
+IO.print(range.iterate(null)) // expect: 1
+IO.print(range.iterate(1)) // expect: 2
+IO.print(range.iterate(2)) // expect: 3
+IO.print(range.iterate(3)) // expect: false
+IO.print(range.iterate(4)) // expect: false
+
+// Exclusive
+range = 1...3
+IO.print(range.iterate(null)) // expect: 1
+IO.print(range.iterate(1)) // expect: 2
+IO.print(range.iterate(2)) // expect: false
+
+// Negative inclusive range.
+range = 3..1
+IO.print(range.iterate(null)) // expect: 3
+IO.print(range.iterate(3)) // expect: 2
+IO.print(range.iterate(2)) // expect: 1
+IO.print(range.iterate(1)) // expect: false
+
+// Negative exclusive range.
+range = 3...1
+IO.print(range.iterate(null)) // expect: 3
+IO.print(range.iterate(3)) // expect: 2
+IO.print(range.iterate(2)) // expect: false
+
+// Empty inclusive range.
+range = 1..1
+IO.print(range.iterate(null)) // expect: 1
+IO.print(range.iterate(1)) // expect: false
+
+// Empty exclusive range.
+range = 1...1
+IO.print(range.iterate(null)) // expect: false