[turbofan] Add backend support for Float32Constant.

src/compiler/instruction.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/instruction.h"
 
 #include "src/compiler/common-operator.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 282 matching lines @@
   return os << "\n";
 }
 
 
 OStream& operator<<(OStream& os, const Constant& constant) {
   switch (constant.type()) {
     case Constant::kInt32:
       return os << constant.ToInt32();
     case Constant::kInt64:
       return os << constant.ToInt64() << "l";
+    case Constant::kFloat32:
+      return os << constant.ToFloat32() << "f";
     case Constant::kFloat64:
       return os << constant.ToFloat64();
     case Constant::kExternalReference:
       return os << constant.ToExternalReference().address();
     case Constant::kHeapObject:
       return os << Brief(*constant.ToHeapObject());
   }
   UNREACHABLE();
   return os;
 }
@@ skipping 162 matching lines @@
       os << " B" << (*iter)->id();
     }
     os << "\n";
   }
   return os;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8