Project2's LLVM IR size is ~33-44% bigger than project1 due to the fact
that in gpui2 we call async_task::spawn(_local) with impl Future instead
of dyn Future, which leads to quite a few more instantiations of
RawTask.
LLVM-IR size for project2:
| build_type | main | this branch | project1 |
| debug | 2617795 | 2022814 | 1817866 |
| release | 4439033 | 3715086 | 3314489 |
Note that this PR is in line with what was done in GPUI1 (we've also
boxed futures there).
Release Notes:
- N/A
Antonio Scandurra
e4bc03217d