[turbofan] Remove case_count >= 3 limit for switch.

src/compiler/common-operator.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/compiler/common-operator.h"
 
 #include "src/assembler.h"
 #include "src/base/lazy-instance.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
@@ skipping 444 matching lines @@
       return &cache_.kIfExceptionCOperator;
     case IfExceptionHint::kLocallyUncaught:
       return &cache_.kIfExceptionUOperator;
   }
   UNREACHABLE();
   return nullptr;
 }
 
 
 const Operator* CommonOperatorBuilder::Switch(size_t control_output_count) {
-  DCHECK_GE(control_output_count, 3u);        // Disallow trivial switches.
   return new (zone()) Operator(               // --
       IrOpcode::kSwitch, Operator::kKontrol,  // opcode
       "Switch",                               // name
       1, 0, 1, 0, 0, control_output_count);   // counts
 }
 
 
 const Operator* CommonOperatorBuilder::IfValue(int32_t index) {
   return new (zone()) Operator1<int32_t>(      // --
       IrOpcode::kIfValue, Operator::kKontrol,  // opcode
@@ skipping 339 matching lines @@
     Handle<SharedFunctionInfo> shared_info,
     ContextCallingMode context_calling_mode) {
   return new (zone()->New(sizeof(FrameStateFunctionInfo)))
       FrameStateFunctionInfo(type, parameter_count, local_count, shared_info,
                              context_calling_mode);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8