[turbofan] Output file for C1 visualizer.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index e8e1d66602b90606e3728f3590af7af3aecc9511..e8b4f263c9fbf1e59d376f104919b514db083ba3 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -4,6 +4,8 @@
 
 #include <stdlib.h>
 
+#include <fstream>  // NOLINT(readability/streams)
+
 #include "src/v8.h"
 
 #include "src/ast.h"
@@ -1931,6 +1933,12 @@ bool Isolate::Init(Deserializer* des) {
     optimizing_compiler_thread_->Start();
   }
 
+  if (FLAG_trace_turbo) {
+    // Erase the file.
+    std::ofstream turbo_cfg_stream("turbo.cfg",
+                                   std::fstream::out | std::fstream::trunc);
+  }
+
   // If we are deserializing, read the state into the now-empty heap.
   if (!create_heap_objects) {
     des->Deserialize(this);