Add --check-code-pointer flag for debug builds

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 d31948af7db2b4243e3326eb45b79a1db2b1b50b..e74a8c8df0595eb18b2a1478f3d56652d3b7cc28 100644
--- a/runtime/vm/assembler_arm.cc
+++ b/runtime/vm/assembler_arm.cc
@@ -22,9 +22,11 @@
 namespace dart {
 
 DECLARE_FLAG(bool, allow_absolute_addresses);
-DEFINE_FLAG(bool, print_stop_message, true, "Print stop message.");
+DECLARE_FLAG(bool, check_code_pointer);
 DECLARE_FLAG(bool, inline_alloc);
 
+DEFINE_FLAG(bool, print_stop_message, true, "Print stop message.");
+
 uint32_t Address::encoding3() const {
   if (kind_ == Immediate) {
     uint32_t offset = encoding_ & kOffset12Mask;
@@ -1518,6 +1520,9 @@ void Assembler::LoadWordFromPoolOffset(Register rd,
 
 void Assembler::CheckCodePointer() {
 #ifdef DEBUG
+  if (!FLAG_check_code_pointer) {
+    return;
+  }
   Comment("CheckCodePointer");
   Label cid_ok, instructions_ok;
   Push(R0);