[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 a08f73a0725b3a3f1f0918f47a411c3a2d07316c..1ea78aac1793b08c387c789526b9c9a27f44bb68 100644
--- a/src/x64/assembler-x64.h
+++ b/src/x64/assembler-x64.h
@@ -1077,6 +1077,8 @@ class Assembler : public AssemblerBase {
 
   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);
 
@@ -1390,6 +1392,14 @@ class Assembler : public AssemblerBase {
     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()};
     vsd(0x2c, idst, xmm0, src, kF2, k0F, kW1);