[turbofan] Address a couple of Type-related TODOs.

src/compiler/js-global-object-specialization.cc

Index: src/compiler/js-global-object-specialization.cc
diff --git a/src/compiler/js-global-object-specialization.cc b/src/compiler/js-global-object-specialization.cc
index b38aed43e40098b67381d0ca01036b35eff55368..9a0c18cf244ea3e9fc5e9bdb95755b56acd50f92 100644
--- a/src/compiler/js-global-object-specialization.cc
+++ b/src/compiler/js-global-object-specialization.cc
@@ -120,12 +120,10 @@ Reduction JSGlobalObjectSpecialization::ReduceJSLoadGlobal(Node* node) {
   if (property_details.cell_type() == PropertyCellType::kConstantType) {
     // Compute proper type based on the current value in the cell.
     if (property_cell_value->IsSmi()) {
-      property_cell_value_type = type_cache_.kSmi;
+      property_cell_value_type = Type::SignedSmall();
       representation = MachineRepresentation::kTaggedSigned;
     } else if (property_cell_value->IsNumber()) {
-      // TODO(mvstanton): Remove kHeapNumber from type cache, it's just
-      // Type::Number().
-      property_cell_value_type = type_cache_.kHeapNumber;
+      property_cell_value_type = Type::Number();
       representation = MachineRepresentation::kTaggedPointer;
     } else {
       // TODO(turbofan): Track the property_cell_value_map on the FieldAccess