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

tests/compiler/dart2js/cps_ir/operators2_7_test.dart

+// ---- AUTO-GENERATED -------------------
+// This file was autogenerated by running:
+//
+//     dart path/to/up_to_date_test.dart update
+//
+// Do not edit this file by hand.
+// ---------------------------------------
+
+library tests.compiler.dart2js.cps_ir.operators2_7.dart;
+
+import 'runner.dart';
+
+main(args) {
+  runTest("operators2_7.dart", update: args.length > 0 && args[0] == "update");
+}