Properly split dart:_vmservice across sdk and runtime

sdk/lib/vmservice/vmservice_sources.gypi

Index: sdk/lib/vmservice/vmservice_sources.gypi
diff --git a/runtime/lib/vmservice_sources.gypi b/sdk/lib/vmservice/vmservice_sources.gypi
similarity index 58%
copy from runtime/lib/vmservice_sources.gypi
copy to sdk/lib/vmservice/vmservice_sources.gypi
index 9fb590a6f40019d9e2717079877e855562a32a74..97b25829d7de8b228adf7bf8cfcb2335b751683d 100644
--- a/runtime/lib/vmservice_sources.gypi
+++ b/sdk/lib/vmservice/vmservice_sources.gypi
@@ -6,14 +6,13 @@
 
 {
   'sources': [
-    'vmservice/vmservice.dart',
+    'vmservice.dart',
     # The above file needs to be first as it imports required libraries.
-    'vmservice/client.dart',
-    'vmservice/constants.dart',
-    'vmservice/running_isolate.dart',
-    'vmservice/running_isolates.dart',
-    'vmservice/message.dart',
-    'vmservice/message_router.dart',
-    'vmservice.cc',
+    'client.dart',
+    'constants.dart',
+    'running_isolate.dart',
+    'running_isolates.dart',
+    'message.dart',
+    'message_router.dart',
   ],
 }