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

tests/compiler/dart2js/cps_ir/expected/operators_4.js

+// Expectation for test: 
+// var x = 1;
+// get foo => ++x > 10;
+// main() { print(foo && foo); }
+
+function() {
+  var v0 = $.x + 1, line;
+  $.x = v0;
+  L0: {
+    if (v0 > 10) {
+      $.x = v0 = $.x + 1;
+      if (v0 > 10) {
+        line = "true";
+        break L0;
+      }
+      v0 = false;
+    } else
+      v0 = false;
+    line = false === v0 ? "false" : String(v0);
+  }
+  if (typeof dartPrint == "function")
+    dartPrint(line);
+  else if (typeof console == "object" && typeof console.log != "undefined")
+    console.log(line);
+  else if (!(typeof window == "object")) {
+    if (!(typeof print == "function"))
+      throw "Unable to print message: " + String(line);
+    print(line);
+  }
+}