Fixes broken background compile error reporting.

Fixes broken tests in DateTimeFormat and NumberFormat: PluralRules
constructor requires 'new'.

Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I65216a3172595397f5de638c9d5d9d021d3257ce
Reviewed-on: https://chromium-review.googlesource.com/931935
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51488}