Revert "Implement rewind: drop one or more frames from the debugger."

runtime/observatory/tests/service/rewind_optimized_out_test.dart

-// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--error_on_bad_type --error_on_bad_override
-
-import 'dart:developer';
-import 'package:observatory/service_io.dart';
-import 'package:unittest/unittest.dart';
-import 'service_test_common.dart';
-import 'test_helper.dart';
-
-const alwaysInline = "AlwaysInline";
-const noInline = "NeverInline";
-
-int LINE_A = 35;
-int LINE_B = 40;
-int LINE_C = 43;
-int LINE_D = 47;
-
-int global = 0;
-
-@noInline
-b3(x) {
-  int sum = 0;
-  try {
-    for (int i = 0; i < x; i++) {
-      sum += x;
-    }
-  } catch (e) {
-    print("caught $e");
-  }
-  if (global >= 100) {
-    debugger();
-  }
-  global = global + 1;  // Line A
-  return sum;
-}
-
-@alwaysInline
-b2(x) => b3(x);  // Line B
-
-@alwaysInline
-b1(x) => b2(x);  // Line C
-
-test() {
-  while (true) {
-    b1(10000);  // Line D
-  }
-}
-
-var tests = [
-  hasStoppedAtBreakpoint,
-  stoppedAtLine(LINE_A),
-
-  (Isolate isolate) async {
-    // We are at our breakpoint with global=100.
-    var result = await isolate.rootLibrary.evaluate('global');
-    print('global is $result');
-    expect(result.type, equals('Instance'));
-    expect(result.valueAsString, equals('100'));
-
-    // Rewind the top stack frame.
-    bool caughtException;
-    try {
-      result = await isolate.rewind(1);
-      expect(false, isTrue, reason:'Unreachable');
-    } on ServerRpcException catch(e) {
-      caughtException = true;
-      expect(e.code, equals(ServerRpcException.kCannotResume));
-      expect(e.message,
-             'Cannot rewind to frame 1 due to conflicting compiler '
-             'optimizations. Run the vm with --no-prune-dead-locals to '
-             'disallow these optimizations. Next valid rewind frame is 4.');
-    }
-    expect(caughtException, isTrue);
-  },
-];
-
-
-main(args) => runIsolateTests(args, tests, testeeConcurrent: test,
-                              extraArgs:
-                              ['--trace-rewind',
-                               '--prune-dead-locals',
-                               '--enable-inlining-annotations',
-                               '--no-background-compilation',
-                               '--optimization-counter-threshold=10']);