Improve some pointer-related documentation#62822

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bors merged 8 commits intorust-lang:masterfrom

RalfJung:pointers

Jul 26, 2019

Commits on Jul 20, 2019

warn that raw pointers must be aligned when used, and that writes cause drop
RalfJung
committed
references must be aligned; also move up the warning that fn ptrs must be non-NULL
RalfJung
committed

Commits on Jul 21, 2019

Commits on Jul 22, 2019

Commits on Jul 23, 2019