[turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

src/ia32/assembler-ia32.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 942 matching lines @@
   void cvttss2si(Register dst, const Operand& src);
   void cvttss2si(Register dst, XMMRegister src) {
     cvttss2si(dst, Operand(src));
   }
   void cvttsd2si(Register dst, const Operand& src);
   void cvttsd2si(Register dst, XMMRegister src) {
     cvttsd2si(dst, Operand(src));
   }
   void cvtsd2si(Register dst, XMMRegister src);
 
+  void cvtsi2ss(XMMRegister dst, Register src) { cvtsi2ss(dst, Operand(src)); }
+  void cvtsi2ss(XMMRegister dst, const Operand& src);
   void cvtsi2sd(XMMRegister dst, Register src) { cvtsi2sd(dst, Operand(src)); }
   void cvtsi2sd(XMMRegister dst, const Operand& src);
   void cvtss2sd(XMMRegister dst, const Operand& src);
   void cvtss2sd(XMMRegister dst, XMMRegister src) {
     cvtss2sd(dst, Operand(src));
   }
   void cvtsd2ss(XMMRegister dst, const Operand& src);
   void cvtsd2ss(XMMRegister dst, XMMRegister src) {
     cvtsd2ss(dst, Operand(src));
   }
@@ skipping 593 matching lines @@
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_IA32_ASSEMBLER_IA32_H_