Revert changes to patch_sdk

tools/patch_sdk.dart

Index: tools/patch_sdk.dart
diff --git a/tools/patch_sdk.dart b/tools/patch_sdk.dart
index f4ada816497bf9e44d1dc0e52f009ca530ea7956..97e2e12c8c95400bf74a578d9094bbbba212099f 100644
--- a/tools/patch_sdk.dart
+++ b/tools/patch_sdk.dart
@@ -164,10 +164,16 @@ Future _main(List<String> argv) async {
         Uri.parse('dart:$vmserviceName'),
         new CompilerOptions()
           ..setExitCodeOnProblem = true
-          ..sdkSummary = outline
+          // TODO(sigmund): investigate. This should be outline, but it breaks
+          // vm-debug tests. Issue #30111
+          ..sdkSummary = platform
           ..librariesSpecificationUri = vmserviceJsonUri
           ..packagesFileUri = packages);
     Uri vmserviceUri = outDirUri.resolve('$vmserviceName.dill');
+    // TODO(sigmund): remove. This is a workaround because in the VM
+    // doesn't support loading vmservice if it contains external libraries
+    // (there is an assertion that only fails in debug builds). Issue #30111
+    program.libraries.forEach((l) => l.isExternal = false);
     await writeProgramToFile(program, vmserviceUri);
   }