Merge #1779

1779: Upgrade libc to 0.2.127 r=asomers a=rtzoeller

This is the last version of libc which will support Rust 1.46, per rust-lang/libc#2845.

I think we should ship nix 0.25.0 against this version of libc (at some point, not necessarily now), as it will allow us to maintain an MSRV of 1.46, and subsequently upgrade to a later libc immediately after releasing 0.25.0.

Co-authored-by: Ryan Zoeller <rtzoeller@rtzoeller.com>

Cargo.toml

@@ -27,7 +27,7 @@ targets = [
 ]
 
 [dependencies]
-libc = { git = "https://github.com/rust-lang/libc", rev = "8dbd2c9", features = [ "extra_traits" ] }
+libc = { version = "0.2.127", features = [ "extra_traits" ] }
 bitflags = "1.1"
 cfg-if = "1.0"
 pin-utils = { version = "0.1.0", optional = true }