[wasm] Fix set_local appearing in unreachable code.

src/wasm/ast-decoder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/platform/elapsed-timer.h"
 #include "src/signature.h"
 
 #include "src/flags.h"
 #include "src/handles.h"
 #include "src/zone-containers.h"
@@ skipping 885 matching lines @@
           ssa_env_->Kill(SsaEnv::kControlEnd);
         }
         break;
       }
       case kExprSetLocal: {
         int unused = 0;
         uint32_t index;
         LocalType type = LocalOperand(p->pc(), &index, &unused);
         Tree* val = p->last();
         if (type == val->type) {
-          if (builder_) ssa_env_->locals[index] = val->node;
+          if (build()) ssa_env_->locals[index] = val->node;
           p->tree->node = val->node;
         } else {
           error(p->pc(), val->pc, "Typecheck failed in SetLocal");
         }
         break;
       }
       case kExprStoreGlobal: {
         int unused = 0;
         uint32_t index;
         LocalType type = GlobalOperand(p->pc(), &index, &unused);
@@ skipping 657 matching lines @@
       FOREACH_MISC_MEM_OPCODE(DECLARE_OPCODE_CASE)
       FOREACH_SIMPLE_OPCODE(DECLARE_OPCODE_CASE)
 #undef DECLARE_OPCODE_CASE
   }
   UNREACHABLE();
   return 0;
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8