[x64] Implement vcvtsd2si AVX instruction.

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
diff --git a/src/x64/assembler-x64.cc b/src/x64/assembler-x64.cc
index 449dbb59039bb94357c080d32961f597ee16ed9b..b051a43f4dc00a42e3215a7f7025052cc5fdd92b 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -3196,6 +3196,7 @@ void Assembler::cvtsd2ss(XMMRegister dst, const Operand& src) {
 
 
 void Assembler::cvtsd2si(Register dst, XMMRegister src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   emit(0xF2);
   emit_optional_rex_32(dst, src);
@@ -3206,6 +3207,7 @@ void Assembler::cvtsd2si(Register dst, XMMRegister src) {
 
 
 void Assembler::cvtsd2siq(Register dst, XMMRegister src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   emit(0xF2);
   emit_rex_64(dst, src);