rollup merge of #18630 : nikomatsakis/purge-the-bars
rollup merge of #18633 : huonw/target-spec-spelling
rollup merge of #18636 : luqmana/armf
rollup merge of #18644 : luqmana/pefc
rollup merge of #18647 : jbcrail/rename-dragonfly
rollup merge of #18656 : thiagopnts/rename-deprecated-non_uppercase_statics
rollup merge of #18664 : klutzy/getrandom
rollup merge of #18665 : scribu/patch-1
Remove rlibc from the distribution

To make progress on #18585 we're paring down the distribution to theoretically
"only libstd", and this commit makes progress on this by removing the rlibc
crate from the distribution.

The crate has now been moved into an external cargo package located in the rust
lang organization [1]. This is a breaking change due to this removal, and
existing crates depending on `rlibc` should use the Cargo crate instead.

[1]: https://github.com/rust-lang/rlibc

[breaking-change]
cc #18585
rollup merge of #18679 : brson/lint-trait
rollup merge of #18683 : thestinger/typo
rollup merge of #18684 : nathan7/patch-1
rollup merge of #18695 : steveklabnik/gh17023
rollup merge of #18696 : tshakah/patch-1
rollup merge of #18705 : fabricedesre/patch-1
rollup merge of #18707 : japaric/moar-dst
rollup merge of #18708 : qwitwa/master
rollup merge of #18654 : michaelwoerister/lldb-test-timeout
rollup merge of #18691 : subhashb/add_clone_trait_to_filetype
rollup merge of #18625 : alexcrichton/no-more-rlibc