Remove default monomorphic check code from functions and stubs that do not need it.

runtime/vm/assembler_arm.cc

Index: runtime/vm/assembler_arm.cc
diff --git a/runtime/vm/assembler_arm.cc b/runtime/vm/assembler_arm.cc
index 6599e59e717dc0a279eaa182d17d34fba7318013..f0af8c2ce1f47f53cbfcb1fda183bbc424ffb6bc 100644
--- a/runtime/vm/assembler_arm.cc
+++ b/runtime/vm/assembler_arm.cc
@@ -3239,16 +3239,10 @@ void Assembler::LeaveStubFrame() {
 }
 
 
-void Assembler::NoMonomorphicCheckedEntry() {
-  buffer_.Reset();
-  bkpt(0);
-  bkpt(0);
-  ASSERT(CodeSize() == Instructions::kCheckedEntryOffset);
-}
-
-
 // R0 receiver, R9 guarded cid as Smi
 void Assembler::MonomorphicCheckedEntry() {
+  ASSERT(has_single_entry_point_);
+  has_single_entry_point_ = false;
 #if defined(TESTING) || defined(DEBUG)
   bool saved_use_far_branches = use_far_branches();
   set_use_far_branches(false);