[turbofan] remove dependence of InstructionBlock on BasicBlock

src/compiler/instruction-selector.h

 // Copyright 2014 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_COMPILER_INSTRUCTION_SELECTOR_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_H_
 
 #include <map>
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Forward declarations.
+class BasicBlock;
 struct CallBuffer;  // TODO(bmeurer): Remove this.
 class FlagsContinuation;
 class Linkage;
 
-
 typedef ZoneVector<InstructionOperand> InstructionOperandVector;
 
 
 // Instruction selection generates an InstructionSequence for a given Schedule.
 class InstructionSelector FINAL {
  public:
   // Forward declarations.
   class Features;
 
   InstructionSelector(Zone* zone, size_t node_count, Linkage* linkage,
@@ skipping 194 matching lines @@
   BoolVector defined_;
   BoolVector used_;
   IntVector virtual_registers_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_H_