implement stack growth check

[graydon]

Stack growth using segmented stacks needs implementation. There's a GSoC student working on the LLVM side of it. We need to make sure our runtime provides the necessary parts as well and get this working on our tasks. Not sure what the scope of work for us is.

[graydon]

Shifted to rustc

[jruderman]

Fuzzer is hitting this. Can I have a special exit code upon hitting the end of the stack, for now?

[graydon]

https://mail.mozilla.org/pipermail/rust-dev/2011-September/000802.html

[pcwalton]

I have an experimental implementation on the LLVM side of things. Not using the GSoC implementation, as it requires a custom linker, which I don't think we can tolerate.

[brson]

Status update before I go on vacation. Stack growth works now on all platforms, but of course windows doesn't unwind. The stack starts at 768 bytes and grows either in multiples or the minimum required to accommodate the next frame. What's left is reducing the red zone (currently 20k) and upstreaming the LLVM patches.

[graydon]

You're a star, thank you for all this! It's been a huge climb. Enjoy the time off.

[brson]

bb1e797 puts us back on LLVM trunk with our patches merged. Opened #1509 for reducing the red zone. Closing.