[turbofan] Implemented the optional Float32RoundTruncate operator.

src/compiler/opcodes.h

 // Copyright 2013 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_OPCODES_H_
 #define V8_COMPILER_OPCODES_H_
 
 #include <iosfwd>
 
 // Opcodes for control operators.
@@ skipping 289 matching lines @@
   V(Float64Mul)                 \
   V(Float64Div)                 \
   V(Float64Mod)                 \
   V(Float64Max)                 \
   V(Float64Min)                 \
   V(Float64Abs)                 \
   V(Float64Sqrt)                \
   V(Float64RoundDown)           \
   V(Float32RoundUp)             \
   V(Float64RoundUp)             \
+  V(Float32RoundTruncate)       \
   V(Float64RoundTruncate)       \
   V(Float64RoundTiesAway)       \
   V(Float64RoundTiesEven)       \
   V(Float64ExtractLowWord32)    \
   V(Float64ExtractHighWord32)   \
   V(Float64InsertLowWord32)     \
   V(Float64InsertHighWord32)    \
   V(LoadStackPointer)           \
   V(LoadFramePointer)           \
   V(CheckedLoad)                \
@@ skipping 76 matching lines @@
   }
 };
 
 std::ostream& operator<<(std::ostream&, IrOpcode::Value);
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_OPCODES_H_