Refactor HType to get rid of various hacks.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 7e587c1d457c88b2e5cd41adf12fe1246abcea6d..9565a08ebae41a4506a2e5a09f1cf100066b5780 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1976,7 +1976,9 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
 LInstruction* LChunkBuilder::DoCheckHeapObject(HCheckHeapObject* instr) {
   LOperand* value = UseAtStart(instr->value());
   LInstruction* result = new(zone()) LCheckNonSmi(value);
-  if (!instr->value()->IsHeapObject()) result = AssignEnvironment(result);
+  if (!instr->value()->type().IsHeapObject()) {
+    result = AssignEnvironment(result);
+  }
   return result;
 }