Make Runtime_Abort print to stderr instead of stdout.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 2f36063dd6b98d9fa63658f36dbd1041d39582e9..7e49abb0b4a0ac6a808ecce2a5cab18c7ed10cae 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -835,7 +835,7 @@ Handle<JSArray> Isolate::CaptureCurrentStackTrace(
 }
 
 
-void Isolate::PrintStack() {
+void Isolate::PrintStack(FILE* out) {
   if (stack_trace_nesting_level_ == 0) {
     stack_trace_nesting_level_++;
 
@@ -850,7 +850,7 @@ void Isolate::PrintStack() {
     StringStream accumulator(allocator);
     incomplete_message_ = &accumulator;
     PrintStack(&accumulator);
-    accumulator.OutputToStdOut();
+    accumulator.OutputToFile(out);
     InitializeLoggingAndCounters();
     accumulator.Log();
     incomplete_message_ = NULL;
@@ -865,7 +865,7 @@ void Isolate::PrintStack() {
       "\n\nAttempt to print stack while printing stack (double fault)\n");
     OS::PrintError(
       "If you are lucky you may find a partial stack dump on stdout.\n\n");
-    incomplete_message_->OutputToStdOut();
+    incomplete_message_->OutputToFile(out);
   }
 }