compiler-rt: do not depend on `usingnamespace`

The idea is to depend on this language feature as little as possible
with the hopes that it can be adjusted to be less of an anti-pattern.
This also helps self-hosted, which does not yet implement
`usingnamespace`, get closer to being able to build compiler-rt.
fc55814faaAndrew Kelley committed on 8/12/2021, 5:48:54 PMparent6eecc4a
19 files changedLine totals unavailable