Set auto breakpoint at various errors

pkg/dev_compiler/lib/js/es6/dart_sdk.js

Index: pkg/dev_compiler/lib/js/es6/dart_sdk.js
diff --git a/pkg/dev_compiler/lib/js/es6/dart_sdk.js b/pkg/dev_compiler/lib/js/es6/dart_sdk.js
index bb1cb3586a7eae2df9efad353a52702000849de5..1ad0f4e74c140caf90c008dee392f11a1fac4da4 100644
--- a/pkg/dev_compiler/lib/js/es6/dart_sdk.js
+++ b/pkg/dev_compiler/lib/js/es6/dart_sdk.js
@@ -1418,24 +1418,31 @@ dart.isGroundType = function(type) {
   return true;
 };
 dart.throwCastError = function(object, actual, type) {
+  dart.debugger();
   dart.throw(new _js_helper.CastErrorImplementation(object, dart.typeName(actual), dart.typeName(type)));
 };
 dart.throwTypeError = function(object, actual, type) {
+  dart.debugger();
   dart.throw(new _js_helper.TypeErrorImplementation(object, dart.typeName(actual), dart.typeName(type)));
 };
 dart.throwStrongModeCastError = function(object, actual, type) {
+  dart.debugger();
   dart.throw(new _js_helper.StrongModeCastError(object, dart.typeName(actual), dart.typeName(type)));
 };
 dart.throwStrongModeTypeError = function(object, actual, type) {
+  dart.debugger();
   dart.throw(new _js_helper.StrongModeTypeError(object, dart.typeName(actual), dart.typeName(type)));
 };
 dart.throwUnimplementedError = function(message) {
+  dart.debugger();
   dart.throw(new core.UnimplementedError(message));
 };
 dart.throwAssertionError = function() {
+  dart.debugger();
   dart.throw(new core.AssertionError());
 };
 dart.throwNullValueError = function() {
+  dart.debugger();
   dart.throw(new core.NoSuchMethodError(null, new core.Symbol('<Unexpected Null Value>'), null, null, null));
 };
 dart.syncStar = function(gen, E, ...args) {
@@ -1965,10 +1972,15 @@ dart.getOwnPropertyNames = function(obj) {
 dart.getOwnPropertySymbols = function(obj) {
   return Object.getOwnPropertySymbols(obj);
 };
+dart.debugger = function() {
+  debugger;
+};
 dart.throwStrongModeError = function(message) {
+  dart.debugger();
   throw new _js_helper.StrongModeErrorImplementation(message);
 };
 dart.throwInternalError = function(message) {
+  dart.debugger();
   throw Error(message);
 };
 dart.getOwnNamesAndSymbols = function(obj) {