Help testing release candidate / mc-4.8.27-rc1

[Joseph Reagle]

I ran the following and still have lots of warnings during make.

```
╭─reagle at hom ~/tmp/mc-4.8.27-pre1
╰─➤  CFLAGS="-target arm64-apple-macos11" \                                                 130 ↵
   ./configure \
     --host=aarch64-apple-darwin \
     --target=aarch64-apple-darwin \
     --build=aarch64-apple-darwin
```