[compiler] Remove support for concurrent OSR.

src/isolate.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <queue>
 #include <set>
 
@@ skipping 978 matching lines @@
   bool IsDeferredHandle(Object** location);
 #endif  // DEBUG
 
   bool concurrent_recompilation_enabled() {
     // Thread is only available with flag enabled.
     DCHECK(optimizing_compile_dispatcher_ == NULL ||
            FLAG_concurrent_recompilation);
     return optimizing_compile_dispatcher_ != NULL;
   }
 
-  bool concurrent_osr_enabled() const {
-    // Thread is only available with flag enabled.
-    DCHECK(optimizing_compile_dispatcher_ == NULL ||
-           FLAG_concurrent_recompilation);
-    return optimizing_compile_dispatcher_ != NULL && FLAG_concurrent_osr;
-  }
-
   OptimizingCompileDispatcher* optimizing_compile_dispatcher() {
     return optimizing_compile_dispatcher_;
   }
 
   int id() const { return static_cast<int>(id_); }
 
   HStatistics* GetHStatistics();
   CompilationStatistics* GetTurboStatistics();
   HTracer* GetHTracer();
   CodeTracer* GetCodeTracer();
@@ skipping 557 matching lines @@
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_H_