Andrew Brown abrown

After merging rust-lang/compiler-team#574 I got side-tracked on other work, but here is a description of how I configured my rustc environment in order to start adding and testing the new wasm32-wasi-threads target. Don't be surprised if I forgot a step or left some TODOs in place — there was some trial-and-error involved in getting to this point!

First, in order to get things working locally, I build a local copy of a WASI sysroot from wasi-libc: make && make THREAD_MODEL=posix (sysroot/share should now contain files for both targets--wasm32-wasi and wasm32-wasi-threads)
Then, in my rust project, I point my config.toml to look at the local WASI sysroot I just built; I do this for both targets (the existing one and the one we're about to add):
```
[target.wasm32-wasi]
wasi-root = ".../wasi-libc/sysroot"
[target.wasm32-wasi-threads]
wasi-root = ".../w
```

	#!/bin/bash
	set -e

	# This script automates the process of rebasing some fixed-up commits (e.g. from a PR review) on the default branch
	# of a remote repository. It expects changes to have been committed with `git commit --fixup ...` and to have the
	# changed branch currently checked out.

	# Retrieve the default branch of the origin remote.
	DEFAULT_BRANCH=$(git symbolic-ref refs/remotes/origin/HEAD \| sed 's@^refs/remotes/origin/@@')
	(set -x; git fetch origin $DEFAULT_BRANCH:$DEFAULT_BRANCH)

	.DEFAULT_GOAL = run
	FLAGS := -Wall -Wextra
	PERF := perf stat -r 10 -ddd
	NUM_ITERATIONS := 10000000
	# for reference of automatic variables, https://www.gnu.org/software/make/manual/html_node/Automatic-Variables.html


	# basic utilities
	clean:
	rm -rf build