stage1: Fix generation of pass-by-value args in async fns
The mismatch between the argument slot type in the frame structure and
the one used in the store operation made the generated code write
garbage over the nearby fields.
Fixes #7104
6624f9cd5cLemonBoy committed on 11/16/2020, 6:37:49 PM· committed by Andrew Kelleyparent7d0c461