Emit an early error when BindingPatterns are used in a VariableDeclaration
or LexicalBinding without an Initializer.

BUG=v8:4532
LOG=N
R=adamk@chromium.org, rossberg@chromium.org, wingo@igalia.com

Review URL: https://codereview.chromium.org/1416753009

Cr-Commit-Position: refs/heads/master@{#31802}