Implement HChange support for Smis and use it in Load/StoreNameField

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 691894c0e2cb4eb92fdad51bf9cbbed5c0c29fc1..87d631540c67997851a5c71b5bcbf5952abbb26f 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -474,6 +474,7 @@ void MacroAssembler::AssertFastElements(Register elements) {
 void MacroAssembler::Check(Condition cc, const char* msg) {
   Label L;
   j(cc, &L, Label::kNear);
+  int3();
   Abort(msg);
   // Control will not return here.
   bind(&L);