Revert of [turbofan] Implemented the TruncateFloat32ToInt64 TurboFan operator.

src/x64/assembler-x64.h

Index: src/x64/assembler-x64.h
diff --git a/src/x64/assembler-x64.h b/src/x64/assembler-x64.h
index 1ea78aac1793b08c387c789526b9c9a27f44bb68..a08f73a0725b3a3f1f0918f47a411c3a2d07316c 100644
--- a/src/x64/assembler-x64.h
+++ b/src/x64/assembler-x64.h
@@ -1077,8 +1077,6 @@
 
   void cvttsd2si(Register dst, const Operand& src);
   void cvttsd2si(Register dst, XMMRegister src);
-  void cvttss2siq(Register dst, XMMRegister src);
-  void cvttss2siq(Register dst, const Operand& src);
   void cvttsd2siq(Register dst, XMMRegister src);
   void cvttsd2siq(Register dst, const Operand& src);
 
@@ -1391,14 +1389,6 @@
   void vcvttsd2si(Register dst, const Operand& src) {
     XMMRegister idst = {dst.code()};
     vsd(0x2c, idst, xmm0, src, kF2, k0F, kW0);
-  }
-  void vcvttss2siq(Register dst, XMMRegister src) {
-    XMMRegister idst = {dst.code()};
-    vsd(0x2c, idst, xmm0, src, kF3, k0F, kW1);
-  }
-  void vcvttss2siq(Register dst, const Operand& src) {
-    XMMRegister idst = {dst.code()};
-    vsd(0x2c, idst, xmm0, src, kF3, k0F, kW1);
   }
   void vcvttsd2siq(Register dst, XMMRegister src) {
     XMMRegister idst = {dst.code()};