Fix --local-rust-root option on Windows
Remove ty_mac
auto merge of #10590 : sanxiyn/rust/ty-mac, r=thestinger
auto merge of #10584 : klutzy/rust/local-rust-root, r=alexcrichton

Fixes #8756.
remove segmented stacks from the manual
auto merge of #10587 : thestinger/rust/stack, r=pcwalton
`std::ptr::read_ptr` now takes `*T` instead of `*mut T`

Closes #10579
auto merge of #10595 : hatahet/rust/master, r=thestinger

Closes #10579