Hard fail on ddc sdk build error

pkg/dev_compiler/tool/build_sdk.dart

Index: pkg/dev_compiler/tool/build_sdk.dart
diff --git a/pkg/dev_compiler/tool/build_sdk.dart b/pkg/dev_compiler/tool/build_sdk.dart
index 99d84e7240f77b74e342725febe8996d995aa406..91812eec3b212641adbe1eb33d12f2e770742bed 100644
--- a/pkg/dev_compiler/tool/build_sdk.dart
+++ b/pkg/dev_compiler/tool/build_sdk.dart
@@ -51,5 +51,8 @@ main(List<String> arguments) {
     'dart:web_gl',
     'dart:web_sql'
   ]);
-  compile(args);
+
+  if (compile(args) != 0) {
+    throw 'SDK build failed.';

[Jennifer Messerly, 2017/01/21 00:55:27]

you don't need a throw. You can just return here, that will set the exit code.

The lack of "return" was most likely an oversight.

+  }
 }