use high entropy ASLR on 64-bit Windows

[thestinger]

MinGW-w64 doesn't expose the necessary flag yet, so I'll look into adding it to their linker. It should be as easy as adding support for an extra flag there and then passing the switch from the Rust compiler.

[thestinger]

https://sourceware.org/ml/gdb-patches/2014-08/msg00359.html

[floatingatoll]

gdb-patches 301'd to the binutils list:
https://sourceware.org/ml/binutils/2014-08/msg00167.html

which accepted the patch:
https://sourceware.org/ml/binutils/2014-08/msg00177.html

[steveklabnik]

closing in favor of #16514

[thestinger]

This is a separate issue from #16514.

[steveklabnik]

Triage: not sure if anything has changed here, but I don't think so.