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

tests/compiler/dart2js/cps_ir/expected/operators_2.js

+// Expectation for test: 
+// var x = 1;
+// foo() => ++x > 10;
+// main() {
+//   print(foo() ? "hello world" : "bad bad");
+// }
+
+function() {
+  var v0 = $.x + 1;
+  $.x = v0;
+  v0 = v0 > 10 ? "hello world" : "bad bad";
+  if (typeof dartPrint == "function")
+    dartPrint(v0);
+  else if (typeof console == "object" && typeof console.log != "undefined")
+    console.log(v0);
+  else if (!(typeof window == "object")) {
+    if (!(typeof print == "function"))
+      throw "Unable to print message: " + String(v0);
+    print(v0);
+  }
+}