[turbofan] Drop V8_TURBOFAN_BACKEND and V8_TURBOFAN_TARGET defines.

test/cctest/compiler/test-linkage.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/parser.h"
 #include "src/zone.h"
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node.h"
 #include "src/compiler/operator.h"
 #include "src/compiler/pipeline.h"
 #include "src/compiler/schedule.h"
 #include "test/cctest/cctest.h"
 
-#if V8_TURBOFAN_TARGET
-
 using namespace v8::internal;
 using namespace v8::internal::compiler;
 
 static Operator dummy_operator(IrOpcode::kParameter, Operator::kNoWrite,
                                "dummy", 0, 0, 0, 0, 0, 0);
 
 // So we can get a real JS function.
 static Handle<JSFunction> Compile(const char* source) {
   Isolate* isolate = CcTest::i_isolate();
   Handle<String> source_code = isolate->factory()
@@ skipping 72 matching lines @@
 
 
 TEST(TestLinkageRuntimeCall) {
   // TODO(titzer): test linkage creation for outgoing runtime calls.
 }
 
 
 TEST(TestLinkageStubCall) {
   // TODO(titzer): test linkage creation for outgoing stub calls.
 }
-
-#endif  // V8_TURBOFAN_TARGET