Mark lazily-patched native calls correctly as patchable.

runtime/vm/flow_graph_compiler_arm64.cc

Index: runtime/vm/flow_graph_compiler_arm64.cc
diff --git a/runtime/vm/flow_graph_compiler_arm64.cc b/runtime/vm/flow_graph_compiler_arm64.cc
index 09ff218beb60a3e3814e804d0546164feee70e5a..862221ed42e586a98253b38d5c108401288545de 100644
--- a/runtime/vm/flow_graph_compiler_arm64.cc
+++ b/runtime/vm/flow_graph_compiler_arm64.cc
@@ -1090,6 +1090,16 @@ void FlowGraphCompiler::GenerateCall(TokenPosition token_pos,
 }
 
 
+void FlowGraphCompiler::GeneratePatchableCall(TokenPosition token_pos,
+                                              const StubEntry& stub_entry,
+                                              RawPcDescriptors::Kind kind,
+                                              LocationSummary* locs) {
+  __ BranchLinkPatchable(stub_entry);
+  AddCurrentDescriptor(kind, Thread::kNoDeoptId, token_pos);
+  RecordSafepoint(locs);
+}
+
+
 void FlowGraphCompiler::GenerateDartCall(intptr_t deopt_id,
                                          TokenPosition token_pos,
                                          const StubEntry& stub_entry,