Define c_char using cfg_if rather than repeating 40-line cfg Libstd has a 40-line cfg that defines the targets on which `c_char` is unsigned, and then repeats the same cfg with `not(…)` for the targets on which `c_char` is signed. This PR replaces it with a `cfg_if!` in which an `else` takes care of the signed case. I confirmed that `x.py doc library/std` inlines the type alias because c_char_definition is not a publicly accessible path:  |
||
|---|---|---|
| .. | ||
| benches | ||
| primitive_docs | ||
| src | ||
| tests | ||
| build.rs | ||
| Cargo.toml | ||