Simplify stack check instruction in Crankshaft.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
===================================================================
--- src/ia32/lithium-ia32.cc	(revision 10109)
+++ src/ia32/lithium-ia32.cc	(working copy)
@@ -2328,15 +2328,9 @@
 
 
 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
-  if (instr->is_function_entry()) {
-    LOperand* context = UseFixed(instr->context(), esi);
-    return MarkAsCall(new(zone()) LStackCheck(context), instr);
-  } else {
-    ASSERT(instr->is_backwards_branch());
-    LOperand* context = UseAny(instr->context());
-    return AssignEnvironment(
-        AssignPointerMap(new(zone()) LStackCheck(context)));
-  }
+  LOperand* context = UseAny(instr->context());
+  return AssignEnvironment(
+      AssignPointerMap(new(zone()) LStackCheck(context)));
 }