VM: Set breakpoints on x64 and arm64 without patching code.

runtime/vm/code_patcher_arm.cc

Index: runtime/vm/code_patcher_arm.cc
diff --git a/runtime/vm/code_patcher_arm.cc b/runtime/vm/code_patcher_arm.cc
index 8cbe89ca1806e7873edd82588cc9dad4e4ca7135..b633fb77a1f0f539c7e816365669f94ae56d8d88 100644
--- a/runtime/vm/code_patcher_arm.cc
+++ b/runtime/vm/code_patcher_arm.cc
@@ -39,17 +39,6 @@ void CodePatcher::PatchInstanceCallAt(uword return_address,
 }
 
 
-int32_t CodePatcher::GetPoolOffsetAt(uword return_address) {
-  UNIMPLEMENTED();
-  return 0;
-}
-
-
-void CodePatcher::SetPoolOffsetAt(uword return_address, int32_t offset) {
-  UNIMPLEMENTED();
-}
-
-
 void CodePatcher::InsertCallAt(uword start, uword target) {
   // The inserted call should not overlap the lazy deopt jump code.
   ASSERT(start + CallPattern::LengthInBytes() <= target);