cpsir unittests: move all unittests into individual files and test runners.

tests/compiler/dart2js/cps_ir/expected/argument_refinement_20.js

Index: tests/compiler/dart2js/cps_ir/expected/argument_refinement_20.js
diff --git a/tests/compiler/dart2js/cps_ir/expected/argument_refinement_20.js b/tests/compiler/dart2js/cps_ir/expected/argument_refinement_20.js
new file mode 100644
index 0000000000000000000000000000000000000000..915d2371ceecd863ed9bcf21a46b4f14ce871b2b
--- /dev/null
+++ b/tests/compiler/dart2js/cps_ir/expected/argument_refinement_20.js
@@ -0,0 +1,21 @@
+// Expectation for test: 
+// main() {
+//   var x = int.parse('1233');
+//   var y = int.parse('1234');
+//   print(x / 2);
+//   print(x is num);
+//   print(y is num);
+//   print(x * y);
+//   print(y is num);
+// }
+
+function() {
+  var x = P.int_parse("1233", null, null), y = P.int_parse("1234", null, null), v0 = typeof y === "number";
+  P.print(J.$div$n(x, 2));
+  P.print(true);
+  P.print(v0);
+  if (!v0)
+    throw H.wrapException(H.argumentErrorValue(y));
+  P.print(x * y);
+  P.print(true);
+}