Fix build for LLVM < 18 #270

	---
	name: macOS CI
	on: [push, pull_request]

	jobs:
	build:
	name: macOS
	strategy:
	fail-fast: false
	matrix:
	os: [macos-12]
	build: [Debug, RelWithDebInfo]

	runs-on: ${{matrix.os}}
	env:
	# for colours in ninja
	CLICOLOR_FORCE: 1

	steps:
	- name: Checkout DG
	uses: actions/checkout@v3

	- name: Install dependencies
	run: brew install ninja ccache llvm@14

	- name: Set environment
	id: env
	run: \|
	echo "CCACHE_BASEDIR=$GITHUB_WORKSPACE" >> $GITHUB_ENV
	echo "CCACHE_DIR=$GITHUB_WORKSPACE/.ccache" >> $GITHUB_ENV
	echo "CCACHE_COMPRESS=true" >> $GITHUB_ENV
	echo "CCACHE_COMPRESSLEVEL=6" >> $GITHUB_ENV
	echo "CCACHE_MAXSIZE=400M" >> $GITHUB_ENV

	echo "/usr/local/opt/ccache/libexec" >> $GITHUB_PATH

	echo "::set-output name=timestamp::$(date -u +%Y-%m-%dT%H:%M:%S%z)"

	- name: Set-up ccache
	uses: actions/cache@v3
	with:
	path: .ccache
	key: ${{matrix.os}}-${{matrix.build}}-${{steps.env.outputs.timestamp}}
	restore-keys: ${{matrix.os}}-${{matrix.build}}

	- name: Configure CMake project
	run: \|
	cmake -S. \
	-B_build \
	-GNinja \
	-DCMAKE_BUILD_TYPE:STRING=${{matrix.build}} \
	-DUSE_SANITIZERS:BOOL=ON \
	-DLLVM_DIR:PATH="$($(brew --prefix llvm@14)/bin/llvm-config --cmakedir)"
	env:
	# for coloured output
	CFLAGS: -fcolor-diagnostics
	CXXFLAGS: -fcolor-diagnostics

	- name: Build
	run: cmake --build _build

	- name: Run tests
	# TODO: turn off the detection of leaks, we're working on it
	run: ASAN_OPTIONS=detect_leaks=0 cmake --build _build --target check

	- name: ccache statistics
	run: ccache -s

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