[interpreter] Fix GCMole warning.

Fix GCMole warning from r29814 (7877c4e0).

BUG=v8:4280
LOG=N
NOTREECHECKS=true
TBR=machenbach,mstarzinger

Review URL: https://codereview.chromium.org/1243893004

Cr-Commit-Position: refs/heads/master@{#29818}

src/interpreter/interpreter.cc

@@ -35,8 +35,8 @@ void Interpreter::Initialize(bool create_heap_objects) {
       compiler::InterpreterAssembler assembler(isolate_, &zone,        \
                                                Bytecode::k##Name);     \
       Do##Name(&assembler);                                            \
-      handler_table->set(static_cast<int>(Bytecode::k##Name),      \
-                         *assembler.GenerateCode());               \
+      Handle<Code> code = assembler.GenerateCode();                    \
+      handler_table->set(static_cast<int>(Bytecode::k##Name), *code);  \
     }
     BYTECODE_LIST(GENERATE_CODE)
 #undef GENERATE_CODE