[x64] Replace movaps with appropriate vmov* instructions when AVX is enabled.

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 fa69bedb97026bdf48e41046ca55864ca1b049d2..15048dd49719ef6483ad587925118a908dfabd95 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -2744,6 +2744,7 @@ void Assembler::movsd(XMMRegister dst, const Operand& src) {
 
 
 void Assembler::movaps(XMMRegister dst, XMMRegister src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   if (src.low_bits() == 4) {
     // Try to avoid an unnecessary SIB byte.
@@ -2772,6 +2773,7 @@ void Assembler::shufps(XMMRegister dst, XMMRegister src, byte imm8) {
 
 
 void Assembler::movapd(XMMRegister dst, XMMRegister src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   if (src.low_bits() == 4) {
     // Try to avoid an unnecessary SIB byte.
@@ -2950,6 +2952,17 @@ void Assembler::ucomiss(XMMRegister dst, const Operand& src) {
 }
 
 
+void Assembler::movss(XMMRegister dst, XMMRegister src) {
+  DCHECK(!IsEnabled(AVX));
+  EnsureSpace ensure_space(this);
+  emit(0xF3);  // single
+  emit_optional_rex_32(dst, src);
+  emit(0x0F);
+  emit(0x10);  // load
+  emit_sse_operand(dst, src);
+}
+
+
 void Assembler::movss(XMMRegister dst, const Operand& src) {
   DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);