By updating YYLTYPE_IS_TRIVIAL to true, YYSTACK_RELOCATE can be enabled, so
we can dynamically allocate stack size based on needs.

BUG=angleproject:3028

Change-Id: I1b9cc0768cd0c6955589695e703595c56d43f24a
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1593954
Commit-Queue: Yi Xu <yiyix@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>