Use the new fs_read_write functions in rustc internals Uses `fs::read` and `fs::write` (added by #45837) where appropriate, to simplify code and dog-food these new APIs. This also improves performance, when combined with #47324.
NB: This crate is part of the Rust compiler. For an overview of the
compiler as a whole, see
the README.md file found in librustc
.
librustc_back
contains some very low-level details that are
specific to different LLVM targets and so forth.