Add GitHub workflow to run a simple `cargo build` #17

	name: Debug build that doesn't produce a ROM

	on:
	push:
	branches:
	- main
	pull_request:
	branches:
	- main

	env:
	CARGO_TERM_COLOR: always
	LLVM_VERSION: 16.0.4

	jobs:
	build:
	strategy:
	fail-fast: true
	matrix:
	include:

	- os: ubuntu-latest
	llvm_url: https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VERSION}/clang+llvm-${LLVM_VERSION}-x86_64-linux-gnu-ubuntu-22.04.tar.xz

	# No pre-built binaries for amd64 macOS :<
	#
	# - os: macos-latest
	# llvm_url: https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VERSION}/clang+llvm-${LLVM_VERSION}-arm64-apple-darwin22.0.tar.xz

	runs-on: ${{ matrix.os }}

	steps:
	- uses: actions/checkout@v3

	- name: Cache pre-built binaries of LLVM
	id: cache-llvm
	uses: actions/cache@v2
	with:
	path: \|
	llvm/bin/lld
	llvm/bin/ld.lld
	key: llvm-${{ env.LLVM_VERSION }}-${{ matrix.os }}

	- name: Cache of Cargo registry and build artifacts
	id: cache-rust
	uses: actions/cache@v2
	with:
	path: \|
	~/.cargo/bin
	~/.cargo/registry
	~/.cargo/git
	target
	key: rust-${{ env.LLVM_VERSION }}-${{ matrix.os }}-${{ hashFiles('/Cargo.toml', '/Cargo.lock', 'rust-toolchain.toml', '**/config.toml') }}

	- name: Download and extract pre-built LLVM release
	if: steps.cache-llvm.outputs.cache-hit != 'true'
	run: \|
	mkdir -p llvm
	curl -L ${{ matrix.llvm_url }} \| tar xJ --strip-components=1 -C llvm

	- name: Add extracted LLVM binaries to PATH
	run: echo "$GITHUB_WORKSPACE/llvm/bin" >> $GITHUB_PATH

	- name: Debug build of Raku from repo root
	run: cargo build

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