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

runtime/vm/flow_graph_compiler_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1319 matching lines @@
                          *StubCode::CallStaticFunction_entry(),
                          RawPcDescriptors::kOther, locs, function);
   __ Drop(argument_count);
 }
 
 
 Condition FlowGraphCompiler::EmitEqualityRegConstCompare(
     Register reg,
     const Object& obj,
     bool needs_number_check,
-    TokenPosition token_pos) {
+    TokenPosition token_pos,
+    intptr_t deopt_id) {
   if (needs_number_check) {
     ASSERT(!obj.IsMint() && !obj.IsDouble() && !obj.IsBigint());
     __ Push(reg);
     __ PushObject(obj);
     if (is_optimizing()) {
       __ BranchLinkPatchable(
           *StubCode::OptimizedIdenticalWithNumberCheck_entry());
     } else {
       __ BranchLinkPatchable(
           *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 cmp, we need Z computed).
     __ Drop(1);   // Discard constant.
     __ Pop(reg);  // Restore 'reg'.
   } else {
     __ CompareObject(reg, obj);
   }
   return EQ;
 }
 
 
-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) {
     __ Push(left);
     __ Push(right);
     if (is_optimizing()) {
       __ BranchLinkPatchable(
           *StubCode::OptimizedIdenticalWithNumberCheck_entry());
     } else {
       __ BranchLinkPatchable(
           *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 cmp, we need Z computed).
     __ Pop(right);
     __ Pop(left);
   } else {
     __ CompareRegisters(left, right);
   }
   return EQ;
 }
 
 
@@ skipping 376 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   __ PopDouble(reg);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64