VM: Make optimized try-catch work in DBC.

runtime/vm/flow_graph_compiler_dbc.cc

 // Copyright (c) 2016, 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_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 176 matching lines @@
   // Marks either the continuation point in unoptimized code or the
   // deoptimization point in optimized code, after call.
   const intptr_t deopt_id_after = Thread::ToDeoptAfter(instr->deopt_id());
   if (is_optimizing()) {
     // Return/ReturnTOS instruction drops incoming arguments so
     // we have to drop outgoing arguments from the innermost environment.
     // On all other architectures caller drops outgoing arguments itself
     // hence the difference.
     pending_deoptimization_env_->DropArguments(instr->ArgumentCount());
     AddDeoptIndexAtCall(deopt_id_after);
+    // This descriptor is needed for exception handling in optimized code.
+    AddCurrentDescriptor(RawPcDescriptors::kOther,
+                         deopt_id_after, instr->token_pos());
   } else {
     // Add deoptimization continuation point after the call and before the
     // arguments are removed.
-    // In optimized code this descriptor is needed for exception handling.
     AddCurrentDescriptor(RawPcDescriptors::kDeopt,
                          deopt_id_after,
                          instr->token_pos());
   }
 }
 
 
 void CompilerDeoptInfoWithStub::GenerateCode(FlowGraphCompiler* compiler,
                                              intptr_t stub_ix) {
   UNREACHABLE();
@@ skipping 349 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   UNIMPLEMENTED();
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC