Small clean up to create a BUILTIN_LIST_INTL to include in BUILTIN_LIST
rather than having two definitions of BUILTIN_LIST depending on whether
V8_INTL_SUPPORT is enabled.

Change-Id: I05ce83fe478049398392c5204b22961d29eb3622
Reviewed-on: https://chromium-review.googlesource.com/1180967Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55209}