Enable Float32Array_getIndexed on X64 now that cvtss2sd is implemented

runtime/vm/assembler_x64.cc

Index: runtime/vm/assembler_x64.cc
diff --git a/runtime/vm/assembler_x64.cc b/runtime/vm/assembler_x64.cc
index 8bc1d198ef498f98167584dc2f74e652aa0fd468..abbda6cf022ae8eecc35be6972c9da81b0b0970b 100644
--- a/runtime/vm/assembler_x64.cc
+++ b/runtime/vm/assembler_x64.cc
@@ -671,6 +671,28 @@ void Assembler::cvttsd2siq(Register dst, XmmRegister src) {
 }
 
 
+void Assembler::cvtss2sd(XmmRegister dst, XmmRegister src) {
+  ASSERT(src <= XMM7);
+  ASSERT(dst <= XMM7);
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0xF3);
+  EmitUint8(0x0F);
+  EmitUint8(0x5A);
+  EmitXmmRegisterOperand(dst, src);
+}
+
+
+void Assembler::cvtsd2ss(XmmRegister dst, XmmRegister src) {
+  ASSERT(src <= XMM7);
+  ASSERT(dst <= XMM7);
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0xF2);
+  EmitUint8(0x0F);
+  EmitUint8(0x5A);
+  EmitXmmRegisterOperand(dst, src);
+}
+
+
 void Assembler::fldl(const Address& src) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xDD);
@@ -691,6 +713,7 @@ void Assembler::fildl(const Address& src) {
   EmitOperand(5, src);
 }
 
+
 void Assembler::fincstp() {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xD9);