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

tests/compiler/dart2js/cps_ir/expected/argument_refinement_25.js

Index: tests/compiler/dart2js/cps_ir/expected/argument_refinement_25.js
diff --git a/tests/compiler/dart2js/cps_ir/expected/argument_refinement_25.js b/tests/compiler/dart2js/cps_ir/expected/argument_refinement_25.js
new file mode 100644
index 0000000000000000000000000000000000000000..9ebb55a8ea471f68fff614fc0d186aefc8774e3f
--- /dev/null
+++ b/tests/compiler/dart2js/cps_ir/expected/argument_refinement_25.js
@@ -0,0 +1,19 @@
+// Expectation for test: 
+// main() {
+//   var x = int.parse('1233');
+//   var y = int.parse('1234');
+//   print(x is int);
+//   print(y is int);
+//   print(x.gcd(y));
+//   print(x is int);
+//   print(y is int);
+// }
+
+function() {
+  var x = P.int_parse("1233", null, null), y = P.int_parse("1234", null, null);
+  P.print(typeof x === "number" && Math.floor(x) === x);
+  P.print(typeof y === "number" && Math.floor(y) === y);
+  P.print(J.gcd$1$i(x, y));
+  P.print(true);
+  P.print(true);
+}