Remember deopt-id -> context-level mappings in var descriptors.

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 ea6d34402171f47bb5703d237c5f6efbe47880b2..fa6cd0761fe5c3d0386cfc68e2c9c798cdf596b9 100644
--- a/runtime/vm/flow_graph_compiler_x64.cc
+++ b/runtime/vm/flow_graph_compiler_x64.cc
@@ -1356,7 +1356,8 @@ Condition FlowGraphCompiler::EmitEqualityRegConstCompare(
     Register reg,
     const Object& obj,
     bool needs_number_check,
-    TokenPosition token_pos) {
+    TokenPosition token_pos,
+    intptr_t deopt_id) {
   ASSERT(!needs_number_check ||
          (!obj.IsMint() && !obj.IsDouble() && !obj.IsBigint()));
 
@@ -1374,10 +1375,7 @@ Condition FlowGraphCompiler::EmitEqualityRegConstCompare(
     } else {
       __ CallPatchable(*StubCode::UnoptimizedIdenticalWithNumberCheck_entry());
     }
-    if (token_pos.IsReal()) {
-      AddCurrentDescriptor(RawPcDescriptors::kRuntimeCall, Thread::kNoDeoptId,
-                           token_pos);
-    }
+    AddCurrentDescriptor(RawPcDescriptors::kRuntimeCall, deopt_id, token_pos);
     // Stub returns result in flags (result of a cmpq, we need ZF computed).
     __ popq(reg);  // Discard constant.
     __ popq(reg);  // Restore 'reg'.
@@ -1388,11 +1386,11 @@ Condition FlowGraphCompiler::EmitEqualityRegConstCompare(
 }
 
 
-Condition FlowGraphCompiler::EmitEqualityRegRegCompare(
-    Register left,
-    Register right,
-    bool needs_number_check,
-    TokenPosition token_pos) {
+Condition FlowGraphCompiler::EmitEqualityRegRegCompare(Register left,
+                                                       Register right,
+                                                       bool needs_number_check,
+                                                       TokenPosition token_pos,
+                                                       intptr_t deopt_id) {
   if (needs_number_check) {
     __ pushq(left);
     __ pushq(right);
@@ -1401,10 +1399,7 @@ Condition FlowGraphCompiler::EmitEqualityRegRegCompare(
     } else {
       __ CallPatchable(*StubCode::UnoptimizedIdenticalWithNumberCheck_entry());
     }
-    if (token_pos.IsReal()) {
-      AddCurrentDescriptor(RawPcDescriptors::kRuntimeCall, Thread::kNoDeoptId,
-                           token_pos);
-    }
+    AddCurrentDescriptor(RawPcDescriptors::kRuntimeCall, deopt_id, token_pos);
     // Stub returns result in flags (result of a cmpq, we need ZF computed).
     __ popq(right);
     __ popq(left);