remove redundant code for AsyncStream readline
use Any[] explicitly for a few things in Base that want it, to make it independent of the behavior of map()
Improve manual about array conversion in ccall

Fixes #7034.
Merge pull request #7037 from nalimilan/docs

Improve manual about array conversion in ccall
fix inconsistent representation of mutable flag in type decl syntax
Merge branch 'master' of github.com:JuliaLang/julia