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

runtime/vm/code_patcher_ia32.cc

Index: runtime/vm/code_patcher_ia32.cc
diff --git a/runtime/vm/code_patcher_ia32.cc b/runtime/vm/code_patcher_ia32.cc
index 194aa028dbe40507612571591d02cac8871206f7..08d95b4c8499c4bcbd6672807290e3dd4a7d3a40 100644
--- a/runtime/vm/code_patcher_ia32.cc
+++ b/runtime/vm/code_patcher_ia32.cc
@@ -176,17 +176,6 @@ void CodePatcher::PatchInstanceCallAt(uword return_address,
 }
 
 
-int32_t CodePatcher::GetPoolOffsetAt(uword return_address) {
-  UNREACHABLE();
-  return 0;
-}
-
-
-void CodePatcher::SetPoolOffsetAt(uword return_address, int32_t offset) {
-  UNREACHABLE();
-}
-
-
 void CodePatcher::InsertCallAt(uword start, uword target) {
   // The inserted call should not overlap the lazy deopt jump code.
   ASSERT(start + CallPattern::InstructionLength() <= target);