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

runtime/vm/assembler_arm64.cc

Index: runtime/vm/assembler_arm64.cc
diff --git a/runtime/vm/assembler_arm64.cc b/runtime/vm/assembler_arm64.cc
index 062ad4b026942562e3c65b182b8cd013c52f5915..59c85c380dbed224f270ac583bf8d3ff17a8040d 100644
--- a/runtime/vm/assembler_arm64.cc
+++ b/runtime/vm/assembler_arm64.cc
@@ -22,9 +22,11 @@
 namespace dart {
 
 DECLARE_FLAG(bool, allow_absolute_addresses);
+DECLARE_FLAG(bool, check_code_pointer);
+DECLARE_FLAG(bool, inline_alloc);
+
 DEFINE_FLAG(bool, use_far_branches, false, "Always use far branches");
 DEFINE_FLAG(bool, print_stop_message, false, "Print stop message.");
-DECLARE_FLAG(bool, inline_alloc);
 
 
 Assembler::Assembler(bool use_far_branches)
@@ -1081,6 +1083,9 @@ void Assembler::RestoreCodePointer() {
 
 void Assembler::CheckCodePointer() {
 #ifdef DEBUG
+  if (!FLAG_check_code_pointer) {
+    return;
+  }
   Comment("CheckCodePointer");
   Label cid_ok, instructions_ok;
   Push(R0);