[test] Move CodeAssembler tests to a separate file.

src/compiler/code-assembler.h

 // Copyright 2015 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_CODE_ASSEMBLER_H_
 #define V8_COMPILER_CODE_ASSEMBLER_H_
 
 #include <map>
 
 // Clients of this interface shouldn't depend on lots of compiler internals.
@@ skipping 344 matching lines @@
   // Protected helpers which delegate to RawMachineAssembler.
   Graph* graph() const;
 
   Node* SmiShiftBitsConstant();
 
   // Enables subclasses to perform operations before and after a call.
   virtual void CallPrologue();
   virtual void CallEpilogue();
 
  private:
-  friend class CodeAssemblerTester;
-
   CodeAssembler(Isolate* isolate, Zone* zone, CallDescriptor* call_descriptor,
                 Code::Flags flags, const char* name);
 
   Node* CallN(CallDescriptor* descriptor, Node* code_target, Node** args);
   Node* TailCallN(CallDescriptor* descriptor, Node* code_target, Node** args);
 
   base::SmartPointer<RawMachineAssembler> raw_assembler_;
   Code::Flags flags_;
   const char* name_;
   bool code_generated_;
@@ skipping 36 matching lines @@
   // Map of variables to the list of value nodes that have been added from each
   // merge path in their order of merging.
   std::map<Variable::Impl*, std::vector<Node*>> variable_merges_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CODE_ASSEMBLER_H_