added note about #[macro_escape]
auto merge of #5567 : jbclements/rust/release-note-macro-escape, r=thestinger
auto merge of #5594 : brson/rust/freebsd, r=brson

This condition was added for cygwin support but appears to simply turn
off the normalization of CPU types
Update LLVM for ARM changes
rustllvm: followup latest LLVM