GC: Fix extern and host references #441

	name: CI

	on: [push, pull_request]

	jobs:
	unit_tests:
	name: 'Run unit tests'
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2

	- name: Get Rust stable toolchain
	uses: actions-rs/toolchain@v1
	with:
	toolchain: stable
	override: true

	- name: Run unit tests
	run: cargo test

	spec_tests:
	name: 'Run WebAssembly test suite'
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2

	- name: Get Rust stable toolchain
	uses: actions-rs/toolchain@v1
	with:
	toolchain: stable
	override: true

	- name: Run spec tests
	run: \|
	export PATH=`pwd`:$PATH
	git submodule update --init --recursive
	cargo run --bin spec-test

	# wasi_tests:
	# name: 'Run WASI tests'
	# runs-on: ubuntu-latest
	# steps:
	# - uses: actions/checkout@v2
	#
	# - name: Get Rust stable toolchain
	# uses: actions-rs/toolchain@v1
	# with:
	# toolchain: stable
	# target: wasm32-wasi
	# override: true
	#
	# - name: Get wasmtime
	# run: bash ci/get_wasmtime.sh
	#
	# - name: Build
	# run: cargo build
	#
	# - name: Run tests
	# run: \|
	# export PATH=`pwd`:$PATH
	# cargo run --bin wasi-test

	formatting:
	name: 'Check formatting'
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2

	- name: Get Rust stable toolchain
	uses: actions-rs/toolchain@v1
	with:
	toolchain: stable
	components: rustfmt
	override: true

	- name: Check formatting
	run: cargo fmt --all -- --check

Provide feedback