MIPS: Serializer enable/disable flags need thread safety.

src/mips/assembler-mips.h

Index: src/mips/assembler-mips.h
diff --git a/src/mips/assembler-mips.h b/src/mips/assembler-mips.h
index 4f365e71d210d2d348e187bd0a9266f87675bf67..e4729b2dd428a239670aaa317d7ccc2f37e8239a 100644
--- a/src/mips/assembler-mips.h
+++ b/src/mips/assembler-mips.h
@@ -427,6 +427,11 @@ class CpuFeatures : public AllStatic {
   // is enabled (snapshots must be portable).
   static void Probe();
 
+  // A special case for printing target and features, which we want to do
+  // before initializing the isolate
+  static void SetHintCreatingSnapshot();
+  static void ProbeWithoutIsolate();
+
   // Check whether a feature is supported by the target CPU.
   static bool IsSupported(CpuFeature f) {
     ASSERT(initialized_);
@@ -455,6 +460,9 @@ class CpuFeatures : public AllStatic {
   }
 
  private:
+  static void Probe(bool serializer_enabled);
+  static bool hint_creating_snapshot_;
+
   static bool Check(CpuFeature f, unsigned set) {
     return (set & flag2set(f)) != 0;
   }