Add missing "static" modifiers for async-gen type structs.
Add missing "static" modifiers for async-gen type structs.

cython/cython,scoder/cython,scoder/cython,scoder/cython,da-woods/cython,cython/cython,cython/cython,da-woods/cython,scoder/cython,cython/cython,da-woods/cython,da-woods/cython