Simplify stack check instruction in Crankshaft.

src/hydrogen.cc

Index: src/hydrogen.cc
===================================================================
--- src/hydrogen.cc	(revision 10109)
+++ src/hydrogen.cc	(working copy)
@@ -2333,8 +2333,7 @@
     AddSimulate(AstNode::kDeclarationsId);
 
     HValue* context = environment()->LookupContext();
-    AddInstruction(
-        new(zone()) HStackCheck(context, HStackCheck::kFunctionEntry));
+    AddInstruction(new(zone()) HStackCheck(context));
 
     VisitStatements(info()->function()->body());
     if (HasStackOverflow()) return NULL;
@@ -2922,8 +2921,7 @@
   BreakAndContinueScope push(break_info, this);
   AddSimulate(stmt->StackCheckId());
   HValue* context = environment()->LookupContext();
-  HStackCheck* stack_check =
-    new(zone()) HStackCheck(context, HStackCheck::kBackwardsBranch);
+  HStackCheck* stack_check = new(zone()) HStackCheck(context);
   AddInstruction(stack_check);
   ASSERT(loop_entry->IsLoopHeader());
   loop_entry->loop_information()->set_stack_check(stack_check);