Change the allocation of the stdout and stderr collected by Process.runSync

runtime/bin/process.cc

Index: runtime/bin/process.cc
diff --git a/runtime/bin/process.cc b/runtime/bin/process.cc
index fe87daf0635fdd26292cda821b4c524cf124c63c..b14c02949616d91598115967fef0386bcc278c15 100644
--- a/runtime/bin/process.cc
+++ b/runtime/bin/process.cc
@@ -183,10 +183,10 @@ void FUNCTION_NAME(Process_Wait)(Dart_NativeArguments args) {
                     process_stderr,
                     exit_event,
                     &result)) {
-    Dart_Handle out =
-        IOBuffer::Create(result.stdout_data(), result.stdout_length());
-    Dart_Handle err =
-        IOBuffer::Create(result.stderr_data(), result.stderr_length());
+    Dart_Handle out = result.stdout_data();
+    if (Dart_IsError(out)) Dart_PropagateError(out);
+    Dart_Handle err = result.stderr_data();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_Handle list = Dart_NewList(4);
     Dart_ListSetAt(list, 0, Dart_NewInteger(pid));
     Dart_ListSetAt(list, 1, Dart_NewInteger(result.exit_code()));