Use NeedsContext() instead of comparing num_heap_slots().

src/full-codegen/arm/full-codegen-arm.cc

Index: src/full-codegen/arm/full-codegen-arm.cc
diff --git a/src/full-codegen/arm/full-codegen-arm.cc b/src/full-codegen/arm/full-codegen-arm.cc
index 1c22a960c64024de6b111b74c517827f4779b21c..96754ca420c2965afd8902cf1f5387fb5f9b75e6 100644
--- a/src/full-codegen/arm/full-codegen-arm.cc
+++ b/src/full-codegen/arm/full-codegen-arm.cc
@@ -167,7 +167,7 @@ void FullCodeGenerator::Generate() {
   bool function_in_register_r1 = true;
 
   // Possibly allocate a local context.
-  if (info->scope()->num_heap_slots() > 0) {
+  if (info->scope()->NeedsContext()) {
     // Argument to NewContext is the function, which is still in r1.
     Comment cmnt(masm_, "[ Allocate context");
     bool need_write_barrier = true;
@@ -1212,7 +1212,7 @@ MemOperand FullCodeGenerator::ContextSlotOperandCheckExtensions(Variable* var,
   Register temp = r4;
 
   for (Scope* s = scope(); s != var->scope(); s = s->outer_scope()) {
-    if (s->num_heap_slots() > 0) {
+    if (s->NeedsContext()) {
       if (s->calls_sloppy_eval()) {
         // Check that extension is "the hole".
         __ ldr(temp, ContextMemOperand(context, Context::EXTENSION_INDEX));