[turbofan] Add proper conversion operators for int32<->int64.

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_
 
 // Opcodes for control operators.
 #define CONTROL_OP_LIST(V) \
   V(Start)                 \
@@ skipping 182 matching lines @@
   V(Uint32LessThanOrEqual) \
   V(Int64Add)              \
   V(Int64Sub)              \
   V(Int64Mul)              \
   V(Int64Div)              \
   V(Int64UDiv)             \
   V(Int64Mod)              \
   V(Int64UMod)             \
   V(Int64LessThan)         \
   V(Int64LessThanOrEqual)  \
-  V(ConvertInt64ToInt32)   \
-  V(ConvertInt32ToInt64)   \
   V(ChangeInt32ToFloat64)  \
   V(ChangeUint32ToFloat64) \
   V(ChangeFloat64ToInt32)  \
   V(ChangeFloat64ToUint32) \
+  V(ChangeInt32ToInt64)    \
+  V(ChangeUint32ToUint64)  \
+  V(TruncateInt64ToInt32)  \
   V(Float64Add)            \
   V(Float64Sub)            \
   V(Float64Mul)            \
   V(Float64Div)            \
   V(Float64Mod)            \
   V(Float64Equal)          \
   V(Float64LessThan)       \
   V(Float64LessThanOrEqual)
 
 #define VALUE_OP_LIST(V) \
@@ skipping 74 matching lines @@
         return false;
     }
   }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_OPCODES_H_