Fix 'typeof null' canonicalization in crankshaft

src/crankshaft/hydrogen-instructions.cc

Index: src/crankshaft/hydrogen-instructions.cc
diff --git a/src/crankshaft/hydrogen-instructions.cc b/src/crankshaft/hydrogen-instructions.cc
index 3d48d8fb71862d1e486ac6f0cc68911a8759f8a0..55e077bc90b9d95f9b96ba0bbf01af04ce09125a 100644
--- a/src/crankshaft/hydrogen-instructions.cc
+++ b/src/crankshaft/hydrogen-instructions.cc
@@ -1203,7 +1203,6 @@ namespace {
 String* TypeOfString(HConstant* constant, Isolate* isolate) {
   Heap* heap = isolate->heap();
   if (constant->HasNumberValue()) return heap->number_string();
-  if (constant->IsUndetectable()) return heap->undefined_string();
   if (constant->HasStringValue()) return heap->string_string();
   switch (constant->GetInstanceType()) {
     case ODDBALL_TYPE: {
@@ -1232,6 +1231,7 @@ String* TypeOfString(HConstant* constant, Isolate* isolate) {
       return nullptr;
     }
     default:
+      if (constant->IsUndetectable()) return heap->undefined_string();
       if (constant->IsCallable()) return heap->function_string();
       return heap->object_string();
   }