Move global V8::UseCrankshaft() into the Isolate.

src/isolate.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1041 matching lines @@
   void SetData(void* data) { embedder_data_ = data; }
   void* GetData() { return embedder_data_; }
 
   LookupResult* top_lookup_result() {
     return thread_local_top_.top_lookup_result_;
   }
   void SetTopLookupResult(LookupResult* top) {
     thread_local_top_.top_lookup_result_ = top;
   }
 
+  bool use_crankshaft() const { return use_crankshaft_; }
+
   bool initialized_from_snapshot() { return initialized_from_snapshot_; }
 
   double time_millis_since_init() {
     return OS::TimeCurrentMillis() - time_millis_at_init_;
   }
 
   DateCache* date_cache() {
     return date_cache_;
   }
 
@@ skipping 221 matching lines @@
   ConsStringIteratorOp objects_string_compare_iterator_a_;
   ConsStringIteratorOp objects_string_compare_iterator_b_;
   StaticResource<ConsStringIteratorOp> objects_string_iterator_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize>
       regexp_macro_assembler_canonicalize_;
   RegExpStack* regexp_stack_;
   DateCache* date_cache_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize> interp_canonicalize_mapping_;
   CodeStubInterfaceDescriptor* code_stub_interface_descriptors_;
 
+  // True if we are using the Crankshaft optimizing compiler.
+  bool use_crankshaft_;
+
   // True if this isolate was initialized from a snapshot.
   bool initialized_from_snapshot_;
 
   // Time stamp at initialization.
   double time_millis_at_init_;
 
 #if V8_TARGET_ARCH_ARM && !defined(__arm__) || \
     V8_TARGET_ARCH_MIPS && !defined(__mips__)
   bool simulator_initialized_;
   HashMap* simulator_i_cache_;
@@ skipping 207 matching lines @@
 
 // Mark the native context with out of memory.
 inline void Context::mark_out_of_memory() {
   native_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_