Use CodeSourceMap for stack traces (still JIT only).

runtime/vm/flow_graph_compiler_x64.cc

Index: runtime/vm/flow_graph_compiler_x64.cc
diff --git a/runtime/vm/flow_graph_compiler_x64.cc b/runtime/vm/flow_graph_compiler_x64.cc
index fa35f47106004967760a2fe9d89f6e8e3b423004..6c69c8062be31eaeab8bcd0b3e87eced12d3850d 100644
--- a/runtime/vm/flow_graph_compiler_x64.cc
+++ b/runtime/vm/flow_graph_compiler_x64.cc
@@ -1279,9 +1279,8 @@ void FlowGraphCompiler::EmitMegamorphicInstanceCall(
     if (try_index == CatchClauseNode::kInvalidTryIndex) {
       try_index = CurrentTryIndex();
     }
-    pc_descriptors_list()->AddDescriptor(
-        RawPcDescriptors::kOther, assembler()->CodeSize(), Thread::kNoDeoptId,
-        token_pos, try_index);
+    AddDescriptor(RawPcDescriptors::kOther, assembler()->CodeSize(),
+                  Thread::kNoDeoptId, token_pos, try_index);
   } else if (is_optimizing()) {
     AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                          token_pos);