Simplify pushing function argument for context allocation.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 5afaf2f5051d5ccc9cf0e4b53e722484ba7ff111..5f3185d3c667cb13adde61ba6fae9822643352ac 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -8492,16 +8492,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_PushWithContext) {
     }
   }
 
-  JSFunction* function;
-  if (args[1]->IsSmi()) {
-    // A smi sentinel indicates a context nested inside global code rather
-    // than some function.  There is a canonical empty function that can be
-    // gotten from the global context.
-    function = isolate->context()->global_context()->closure();
-  } else {
-    function = JSFunction::cast(args[1]);
-  }
-
+  JSFunction* function = JSFunction::cast(args[1]);
   Context* context;
   MaybeObject* maybe_context =
       isolate->heap()->AllocateWithContext(function,
@@ -8518,15 +8509,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_PushCatchContext) {
   ASSERT(args.length() == 3);
   String* name = String::cast(args[0]);
   Object* thrown_object = args[1];
-  JSFunction* function;
-  if (args[2]->IsSmi()) {
-    // A smi sentinel indicates a context nested inside global code rather
-    // than some function.  There is a canonical empty function that can be
-    // gotten from the global context.
-    function = isolate->context()->global_context()->closure();
-  } else {
-    function = JSFunction::cast(args[2]);
-  }
+  JSFunction* function = JSFunction::cast(args[2]);
   Context* context;
   MaybeObject* maybe_context =
       isolate->heap()->AllocateCatchContext(function,
@@ -8543,15 +8526,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_PushBlockContext) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
   SerializedScopeInfo* scope_info = SerializedScopeInfo::cast(args[0]);
-  JSFunction* function;
-  if (args[1]->IsSmi()) {
-    // A smi sentinel indicates a context nested inside global code rather
-    // than some function.  There is a canonical empty function that can be
-    // gotten from the global context.
-    function = isolate->context()->global_context()->closure();
-  } else {
-    function = JSFunction::cast(args[1]);
-  }
+  JSFunction* function = JSFunction::cast(args[1]);
   Context* context;
   MaybeObject* maybe_context =
       isolate->heap()->AllocateBlockContext(function,