rollup merge of #24921: tamird/bitflags-associated-const

Conflicts:
	src/librustc/lib.rs

diff --cc src/librustc/lib.rs
index b0b1b4df6e30699ef649fcc99a43556503c64b34,253285ac04a37eae77c42664d13063ebd1edbe9c..aeb08464ff566554d9a0b6cf21615c1c59a8063c
--- 1/src/librustc/lib.rs
--- 2/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@@ -29,8 -30,10 +30,11 @@@
  #![feature(box_syntax)]
  #![feature(collections)]
  #![feature(core)]
++#![feature(fs_canonicalize)]
  #![feature(hash)]
+ #![feature(into_cow)]
  #![feature(libc)]
+ #![feature(path_ext)]
  #![feature(quote)]
  #![feature(rustc_diagnostic_macros)]
  #![feature(rustc_private)]

diff --cc src/librustc_llvm/lib.rs
Simple merge