Remove some leftovers of full-codegen's generators implementation.

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index c0c8a3b9537f11575c4887fc8446e363981c517c..9142c18a08266a141a25e9185552197dc1580308 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -131,8 +131,6 @@ void FullCodeGenerator::Generate() {
 
   { Comment cmnt(masm_, "[ Allocate locals");
     int locals_count = info->scope()->num_stack_slots();
-    // Generators allocate locals, if any, in context slots.
-    DCHECK(!IsGeneratorFunction(info->literal()->kind()) || locals_count == 0);
     OperandStackDepthIncrement(locals_count);
     if (locals_count == 1) {
       __ PushRoot(Heap::kUndefinedValueRootIndex);