In VisitArrayLiteral(), we stopped creating boilerplates during
 compilation. This created a bug, because we'd emit an HStoreKeyed with an
 ElementsKind based on the initial elements kind of the boilerplate. Since
 boilerplates may transition as part of elements transition feedback, this can
 lead to incorrect values (storing a smi in a double array).

BUG=chromium:606021

Review-Url: https://codereview.chromium.org/2000673002
Cr-Commit-Position: refs/heads/master@{#36408}