stage1: Fix emission of sret annotation for LLVM

LLVM12 deprecated `sret` and replaced it with the `sret(<Ty>)` form.

Closes #8075
b706b9bce7LemonBoy committed on 2/26/2021, 8:48:27 PM· committed by Andrew Kelleyparent4318017
3 files changedLine totals unavailable