[interpreter] Fix gcmole error after r30404.

BUG=v8:4280
LOG=N
TBR=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1319943002

Cr-Commit-Position: refs/heads/master@{#30406}

test/cctest/test-heap.cc

@@ -723,7 +723,8 @@ TEST(BytecodeArray) {
   SimulateFullSpace(heap->old_space());
   Handle<FixedArray> constant_pool = factory->NewFixedArray(5, TENURED);
   for (int i = 0; i < 5; i++) {
-    constant_pool->set(i, *factory->NewHeapNumber(i));
+    Handle<Object> number = factory->NewHeapNumber(i);
+    constant_pool->set(i, *number);
   }
 
   // Allocate and initialize BytecodeArray