Make CTX allocatable by the register allocator.

runtime/vm/compiler.cc

 // Copyright (c) 2012, 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/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/block_scheduler.h"
@@ skipping 1031 matching lines @@
     func.SetNumOptionalParameters(0, true);
     // Manually generated AST, do not recompile.
     func.SetIsOptimizable(false);
 
     // We compile the function here, even though InvokeFunction() below
     // would compile func automatically. We are checking fewer invariants
     // here.
     ParsedFunction* parsed_function = new ParsedFunction(isolate, func);
     parsed_function->SetNodeSequence(fragment);
     parsed_function->set_default_parameter_values(Object::null_array());
-    parsed_function->EnsureExpressionTemp();
-    fragment->scope()->AddVariable(parsed_function->expression_temp_var());
+    fragment->scope()->AddVariable(parsed_function->EnsureExpressionTemp());
+    fragment->scope()->AddVariable(
+        parsed_function->current_context_var());
     parsed_function->AllocateVariables();
 
     // Non-optimized code generator.
     CompileParsedFunctionHelper(parsed_function, false, Isolate::kNoDeoptId);
 
     const Object& result = PassiveObject::Handle(
         DartEntry::InvokeFunction(func, Object::empty_array()));
     return result.raw();
   } else {
     const Object& result =
       PassiveObject::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart