winpthreads: Add missing `__stdcall` on lazy-binding function pointers
headers: Fix include guard for functiondiscoverykeys_devpkey.h
crt: Include functiondiscoverykeys.h in uuid library
headers: Add new symbols in functiondiscoverykeys.h
crt: Add new APIs in user32 import library
crt: Fix libscrnsave
headers: Avoid false-positive -Wconversion warnings in isnan() macro
headers: Add new symbols in minwinbase.h