[compiler][be] Promote destructured params to temporaries

Addresses a follow-up from the previous PR. Destructured function params are currently not eagerly promoted to temporaries: we wait until PromotedUsedTemporaries. But params _always_ have to be named, so we can promote when constructing HIR.

ghstack-source-id: a6f6657
Pull Request resolved: facebook#30332

Author: felixshiftellecon