VM: [DBC] Fix lazy deoptimization after calls that return no values.

runtime/vm/deopt_instructions.cc

 // Copyright (c) 2013, 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/deopt_instructions.h"
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
 #include "vm/disassembler.h"
@@ skipping 1059 matching lines @@
     intptr_t object_table_index = FindOrAddObjectInTable(source_loc.constant());
     deopt_instr = new (zone()) DeoptConstantInstr(object_table_index);
   } else if (source_loc.IsInvalid() &&
              value->definition()->IsMaterializeObject()) {
     const intptr_t index =
         FindMaterialization(value->definition()->AsMaterializeObject());
     ASSERT(index >= 0);
     deopt_instr = new (zone()) DeoptMaterializedObjectRefInstr(index);
   } else {
     ASSERT(!source_loc.IsInvalid());
-    switch (value->definition()->representation()) {
+#if defined(TARGET_ARCH_DBC)
+    Representation rep =
+        (value == NULL) ? kTagged : value->definition()->representation();
+#else
+    Representation rep = value->definition()->representation();
+#endif
+    switch (rep) {
       case kTagged:
         deopt_instr =
             new (zone()) DeoptWordInstr(ToCpuRegisterSource(source_loc));
         break;
       case kUnboxedMint: {
         if (source_loc.IsPairLocation()) {
           PairLocation* pair = source_loc.AsPairLocation();
           deopt_instr =
               new (zone()) DeoptMintPairInstr(ToCpuRegisterSource(pair->At(0)),
                                               ToCpuRegisterSource(pair->At(1)));
@@ skipping 228 matching lines @@
                           Smi* offset,
                           TypedData* info,
                           Smi* reason) {
   intptr_t i = index * kEntrySize;
   *offset ^= table.At(i);
   *info ^= table.At(i + 1);
   *reason ^= table.At(i + 2);
 }
 
 }  // namespace dart