Rust fixes on Linux and Windows
Add rust toolchain mappings for Linux ARM
bootstrap: MSYS2 has moved from pkg-config to pkgconf
pacman keeps swapping between the two:
:: mingw-w64-ucrt-x86_64-pkg-config and mingw-w64-ucrt-x86_64-pkgconf are in conflict. Remove mingw-w64-ucrt-x86_64-pkgconf? [Y/n]
...
:: Replace mingw-w64-ucrt-x86_64-pkg-config with ucrt64/mingw-w64-ucrt-x86_64-pkgconf? [Y/n]
Edited by Nirbheek Chauhan