Auto merge of #32828 - vadimcn:symlinks, r=alexcrichton

Do not rely on file extensions after path canonicalization.

Rustc does not recognize libraries which are symlinked to files having extension other than .rlib. The problem is that find_library_crate calls fs::canonicalize on found library paths, but then the resulting path is passed to get_metadata_section, which assumes it will end in ".rlib" if it's an rlib (from https://internals.rust-lang.org/t/is-library-path-canonicalization-worth-it/3206).

cc #29433