Remove cancel and make crash exit with code 253.

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
index 78f901fbc694567961f5f4db146ac23691d5323b..4bdf9543f872bac29c0eda3144148c28d639678b 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
@@ -1832,7 +1832,7 @@ class JavaScriptBackend extends Backend {
       } else if (cls == noThrowsClass) {
         hasNoThrows = true;
         if (!Elements.isStaticOrTopLevelFunction(element)) {
-          compiler.internalErrorOnElement(
+          compiler.internalError(
               element,
               "@NoThrows() is currently limited to top-level"
               " or static functions");
@@ -1850,11 +1850,11 @@ class JavaScriptBackend extends Backend {
       }
     }
     if (hasNoThrows && !hasNoInline) {
-      compiler.internalErrorOnElement(
+      compiler.internalError(
           element, "@NoThrows() should always be combined with @NoInline");
     }
     if (hasNoSideEffects && !hasNoInline) {
-      compiler.internalErrorOnElement(
+      compiler.internalError(
           element, "@NoSideEffects() should always be combined with @NoInline");
     }
   }