[x64] Fix the assembler and the disassembler.

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 97bdca2387daf1e6bedab49c681e27c7c4f8bffb..d7e458972f309b6256a6bf253b148e0c49543976 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -3790,6 +3790,14 @@ void Assembler::punpckldq(XMMRegister dst, XMMRegister src) {
   emit_sse_operand(dst, src);
 }
 
+void Assembler::punpckldq(XMMRegister dst, const Operand& src) {
+  EnsureSpace ensure_space(this);
+  emit(0x66);
+  emit_optional_rex_32(dst, src);
+  emit(0x0F);
+  emit(0x62);
+  emit_sse_operand(dst, src);
+}
 
 void Assembler::punpckhdq(XMMRegister dst, XMMRegister src) {
   EnsureSpace ensure_space(this);
@@ -4434,7 +4442,8 @@ void Assembler::pmulld(XMMRegister dst, const Operand& src) {
   emit(0x66);
   emit_optional_rex_32(dst, src);
   emit(0x0F);
-  emit(0xF4);
+  emit(0x38);
+  emit(0x40);
   emit_sse_operand(dst, src);
 }
 
@@ -4456,24 +4465,6 @@ void Assembler::pmuludq(XMMRegister dst, const Operand& src) {
   emit_sse_operand(dst, src);
 }
 
-void Assembler::punpackldq(XMMRegister dst, XMMRegister src) {
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x62);
-  emit_sse_operand(dst, src);
-}
-
-void Assembler::punpackldq(XMMRegister dst, const Operand& src) {
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x62);
-  emit_sse_operand(dst, src);
-}
-
 void Assembler::psrldq(XMMRegister dst, uint8_t shift) {
   EnsureSpace ensure_space(this);
   emit(0x66);